9" rear axle conversion?

[GreekGod]

I am looking into changing my rear axle into a 9" Ford. This is for my 2000 Crown Victoria, but I will also see about the same for my 2003 Marauder. As far as I know, no one has done this, except with a race car (and not retaining the factory OEM mounting points).

My goal will be to retain the Watts link, which I have been told is a problem to fit to the 9" design. Because the pinion is (2"?) lower than the 8.8" design, the driveshaft length may also require engineering. A disc brake conversion is another likely necessity, and retaining ABS a consideration.

I understand the 8.8" is normally entirely adequate for street driving, but a 9" would open up many possibilities and great options for the Panther chassis. I've been told the 9" requires ~7 to 9 more horsepower than the 8.8", but for any use other than class racing, it is insignificant. Think NASCAR full floating hubs, with 35 spline axle shafts, and Wilwood disc brakes!

My rear axle consulting engineer is a nationally recognized expert with ~30 years experience, and located close to me in Michigan.

If much interest is shown, a bolt-in (freight shipped) assembly is a future possibility, pending a successful prototype, of course.

http://www.mercurymarauder.net/gallery/data/500/Watts_linkage1.gif

======================

[yjmud]

I would think the abs will be the hardest part the watts I would think a bracket that bolted to the top of the case and to the pinion support should be able to handle what it needs to do

[Krytin]

Very interested in what you find. Not a big fan of the 8.8" rear.

[RR|Suki]

I talked to a friend of mine who is a good rear end builder in Mason, and he was all about trying to get it to work. Our thinking was that when I actually get around to putting real power down a 9" would be great. However, ended up deciding to just put a torsen in her for now since I'm saving for a house. Silly growing up and stuff :bigcry:

Would be very interested to see how this ends up working out

[GreekGod]

... supposedly, Paul's High Performance in Jackson MI changes over to the Ford/Sterling 10.5" (35 spline, 1.5" diameter shafts) axle for Panther upgrades, but I have not talked to them. It is, of course, also a Salisbury (integral) design. I do not know how they would attach a Watts link to the Sterling, but I doubt they come with a threaded hole for the link stud.

Retaining the ABS might be doable.

================

[Comin' in Hot]

I think this is a great idea, but there's always a big "but", If I'm going to break something in my driveline, I would much rather have it be my rear and than a weak link in the transmission somewhere.

[Triple Threat]

I am looking into changing my rear axle into a 9" Ford. This is for my 2000 Crown Victoria, but I will also see about the same for my 2003 Marauder. As far as I know, no one has done this, except with a race car (and not retaining the factory OEM mounting points).

My goal will be to retain the Watts link, which I have been told is a problem to fit to the 9" design. Because the pinion is (2"?) lower than the 8.8" design, the driveshaft length may also require engineering. A disc brake conversion is another likely necessity, and retaining ABS a consideration.

I understand the 8.8" is normally entirely adequate for street driving, but a 9" would open up many possibilities and great options for the Panther chassis. I've been told the 9" requires ~7 to 9 more horsepower than the 8.8", but for any use other than class racing, it is insignificant. Think NASCAR full floating hubs, with 35 spline axle shafts, and Wilwood disc brakes!

My rear axle consulting engineer is a nationally recognized expert with ~30 years experience, and located close to me in Michigan.

If much interest is shown, a bolt-in (freight shipped) assembly is a future possibility, pending a successful prototype, of course.

http://www.mercurymarauder.net/gallery/data/500/Watts_linkage1.gif

======================

A 8.8 is adequate for more than street driving.I have 639 rwhp with 31 spline axels and a Detroit locker.This car is used for drag racing only with no problems.

[MOTOWN]

I have been thinking of this as well, we all know the 8.8 is more than capable, but a 9inch would be plain badazz!

Anything can be fabricated if you are willing to pay for it! to get something like this done with abs, and wattslink its going to be around 4-5k when all is said and done, thats with 35 spline axles ,Lenco billet locker, strange nodular third member, big ford billet end flanges, big disc brakes, gears, etc

[justbob]

I am/was on the same mission. I have spent so much money this year that I am quite literally sick of the car so I have shelved the project till a later date. My 6sp wreaks havoc on the 8.8 and I certainly wouldn't be opposed to letting someone else do the leg work... Looking forward to what you come up with.


Self proclaimed Builder Of Badassery.

Buy it, Break it, Build it BETTER.
"Since 2004"

[fastblackmerc]

Try Strange Engineering, DTS Custom Services & Moser. Any of them can make up whatever you want that will bolt right in.

Got a 9" Ford setup for my sons 3rd gen Camaro... bolted right in.

Checkout Tiger Rear Ends Performance Products..... that would be rally cool to have in a Marauder.

[GreekGod]

Try Strange Engineering, DTS Custom Services & Moser. Any of them can make up whatever you want that will bolt right in.

Got a 9" Ford setup for my sons 3rd gen Camaro... bolted right in.

Checkout Tiger Rear Ends Performance Products..... that would be rally cool to have in a Marauder.

No one makes a bolt in 9". No one! Let me repeat that: NO ONE makes a bolt in 9" for a Panther. SOME will build one, true. Leave the car with them for 2 months, or so, and pay them for their time at an hourly rate.

Reasonably priced bolt in Camaro & Mustang 9" conversions are readily available because they are popular. Panthers - not so popular.

The mounting brackets are a major problem, whether cut off a used housing, or fabricated. Installation on a 9" housing then requires proper alignment of them.

I am local to my fabricator, he is a 30 minute drive away. "Tiger R.E.P.P." appears to be a quick change (only). This is about making a 9" work, without the (many) limitations of the 8.8".

With what I've spent on axle shafts, new gears, and a Detroit Locker on my MM, I could have had big Ford 9" ends welded on, and Strange shafts, also.

[mrjones]

The 8.8 can be built to be plenty strong for the Vic. The only real advantage for the 9 is if you were building a track car and wanted the ability to easily change ratios for different tracks.

[1stMerc]

I am/was on the same mission. I have spent so much money this year that I am quite literally sick of the car so I have shelved the project till a later date. My 6sp wreaks havoc on the 8.8 and I certainly wouldn't be opposed to letting someone else do the leg work... Looking forward to what you come up with.


Self proclaimed Builder Of Badassery.

Buy it, Break it, Build it BETTER.
"Since 2004"

Dang, I thought sure you would be making an announcement you already had this in the works. :D

[GreekGod]

The 8.8 can be built to be plenty strong for the Vic. The only real advantage for the 9 is if you were building a track car and wanted the ability to easily change ratios for different tracks.

The 8.8" is a compromise, at best. There is much more than strength to consider. That's why drag racers prefer the design of the 9". A #4400 car with slicks and over 500 horsepower needs 1.5" axle shafts. If you think smaller diameter shafts are OK, you are not very concerned with safety.

=================

[LANDY]

Lol. There are guys pulling 1.3 60' with a Ford 8.8 at 3400lbs. The 8.8 can hold 1.4x 60' in this cars all day long. Suspension setup and tire choice plays a huge role. In this age one can tune a car with gobs if power to apply it as need it. If you dont have a 1k plus RWHP 4300# car stick or auto. Your wasting time and money.

[GreekGod]

Lol. There are guys pulling 1.3 60' with a Ford 8.8 at 3400lbs. The 8.8 can hold 1.4x 60' in this cars all day long. Suspension setup and tire choice plays a huge role. In this age one can tune a car with gobs if power to apply it as need it. If you dont have a 1k plus RWHP 4300# car stick or auto. Your wasting time and money.

Just because you can do something, doesn't mean you should. If you use 31 spline axles in a 2 ton + car with slicks, you can probably get away with it for a long time. Take away 1,000 pounds, as in a Mustang, and they will last even longer.

The NHRA requires C clip eliminators for certain cars, because it is a safety issue. Safety is never a waste of time and money. The rules are written in blood. Getting rid of the C clips and welding in 9" ends should be job #1 for a Marauder with slicks in 1/4 mile testing. If you include 35 spline 1.5" diameter shafts, there is an additional safety margin over the 31 spline.

============

[Joe Walsh]

Just because you can do something, doesn't mean you should. If you use 31 spline axles in a 2 ton + car with slicks, you can probably get away with it for a long time. Take away 1,000 pounds, as in a Mustang, and they will last even longer.

The NHRA requires C clip eliminators for certain cars, because it is a safety issue. Safety is never a waste of time and money. The rules are written in blood. Getting rid of the C clips and welding in 9" ends should be job #1 for a Marauder with slicks in 1/4 mile testing. If you include 35 spline 1.5" diameter shafts, there is an additional safety margin over the 31 spline.

============

Not to get off topic, but the 9" Ford rear has the bearings pressed on to the axle shafts to retain them vs. C clips in the 8.8" rear.
Can you safely run 9" style pressed on bearings in a 4,400 lb car on a road course?....:dunno:
A 4,400 lb car with good tires and suspension can generate some huge side loads on the axles/bearings.

[sailsmen]

The 8.8" is a compromise, at best. There is much more than strength to consider. That's why drag racers prefer the design of the 9". A #4400 car with slicks and over 500 horsepower needs 1.5" axle shafts. If you think smaller diameter shafts are OK, you are not very concerned with safety.

=================

Many including myself have proved the above to be wrong.
How many have snapped an axle?

[Krytin]

Not to get off topic, but the 9" Ford rear has the bearings pressed on to the axle shafts to retain them vs. C clips in the 8.8" rear.
Can you safely run 9" style pressed on bearings in a 4,400 lb car on a road course?....:dunno:
A 4,400 lb car with good tires and suspension can generate some huge side loads on the axles/bearings.
+1 on that! And the bearings have their own race - they don't use a "hardened" section of the axel shaft. When a bearing fails on the 9" rear you don't automatically loose the shaft!
Plus, after seeing/rebuilding the rear in my car after 100K miles of street driving I have to say the 8.8" rear is marginal at best in the panther platform. I guess that's why taxi/limo garages keep axel kits on the shelf as part of their normal maintenance program!

[sailsmen]

Just because you can do something, doesn't mean you should. If you use 31 spline axles in a 2 ton + car with slicks, you can probably get away with it for a long time. Take away 1,000 pounds, as in a Mustang, and they will last even longer.

The NHRA requires C clip eliminators for certain cars, because it is a safety issue. Safety is never a waste of time and money. The rules are written in blood. Getting rid of the C clips and welding in 9" ends should be job #1 for a Marauder with slicks in 1/4 mile testing. If you include 35 spline 1.5" diameter shafts, there is an additional safety margin over the 31 spline.

============
If you want to be extra safe just don't race. I have seen thousands of races and I have over 260 in the MM with an 8.8. I have seen dozens of wrecks and none due to a snapped rear axle. The axles that I have seen snap do so on launch with no subsequent wreck.
Money would be better spent on a quality helmet, racing seat with harness and a cage.

[GreekGod]

Not to get off topic, but the 9" Ford rear has the bearings pressed on to the axle shafts to retain them vs. C clips in the 8.8" rear.
Can you safely run 9" style pressed on bearings in a 4,400 lb car on a road course?....:dunno:
A 4,400 lb car with good tires and suspension can generate some huge side loads on the axles/bearings.

(On topic):

The typical "big Ford" 9" axle shaft wheel bearing is from the F150, and is a wet tapered roller bearing (I think they are rated #3800). There are also other optional bearings. I am planning to go with NASCAR floating axles, which have opposed taper roller bearings - 3/4 ton/1 ton F250/F350 hubs.

===

[GreekGod]

If you want to be extra safe just don't race. I have seen thousands of races and I have over 260 in the MM with an 8.8. I have seen dozens of wrecks and none due to a snapped rear axle. The axles that I have seen snap do so on launch with no subsequent wreck.
Money would be better spent on a quality helmet, racing seat with harness and a cage.


OK, sailsman, I must defer to your vast experience & knowledge. But, don't you think a helmet, racing seat, harness, & cage is a waste of time & money, also?

These examples must be a 1-in-a-million occurrence? ...

http://www.youtube.com/watch?v=ST6FQV2GBIk

"Just like it says I've been on 31 spline axles for way to long now, a little tire shake and boom. They are 35 spline now" ...
http://www.youtube.com/watch?v=4XwDW7CdvTE

Wheel passes car:
http://www.youtube.com/watch?v=UguuAiVex7E

http://www.youtube.com/watch?v=ZuEthx26Pkg

http://www.youtube.com/watch?v=8F4BL2CM5cU

[sailsmen]

Please read my post -" I have seen dozens of wrecks and none due to a snapped rear axle. The axles that I have seen snap do so on launch with no subsequent wreck.
Money would be better spent on a quality helmet, racing seat with harness and a cage."

It's your money spend it how you please.

I strongly disagree with your statement - "A #4400 car with slicks and over 500 horsepower needs 1.5" axle shafts. If you think smaller diameter shafts are OK, you are not very concerned with safety."- based on actual real World experience and the opinions of some of those who have far more expertise than myself.

[lifespeed]

I very much appreciate the strength, reliability and near-zero maintenance of proper tapered roller bearings and floating axles. This is absolutely how it should have been done from the beginning. I hate axle designs that roll the bearing directly on the axle and transfer side loads to the diff through C-clips.

That said, there are probably not too many of us with enough power to justify the cost. But it is a cool idea.

[GreekGod]

on launch with no subsequent wreck

Little duct tape, and she's good as new ...
http://www.youtube.com/watch?v=ST6FQV2GBIk

Get out the spare! ...
http://www.youtube.com/watch?v=8F4BL2CM5cU

[GreekGod]

We decided the 9" is out - too many problems to make it work.

Looks like we will go with a bolt-in modified stock/OEM 8.8".

The details:

Detroit Truetrac 33 spline (Eaton)



Moser Hobby Stock Circle Track Axle Package (forged ends, 5/8” studs, 45mm bearings)



Girdle cover + axle braces



Explorer or Wilwood disc brakes



Welded axle tubes



My used 3.27 ring & pinion, or a new 3.08

[lifespeed]

Do you still get tapered rollers? Floating axles?

[GreekGod]

Do you still get tapered rollers? Floating axles?
I'm sure they are tapered, they are larger than the F150 (5/8 ton) rear wheel bearings - semi floating:

Moser "Hobby Stock Circle Track Axle Package" ...

SKU: CTHOBBYSTKPKG Availability: In stock.
$695.00Quick Overview
MADE THE AMERICAN WAY IN THE USA!
*This item will ship two business days after online transaction is completed.
Product Description

We offer the strongest Hobby Stock flanged axle on the market! These custom alloy axles feature a giant 1.774" bearing seat for use with a 45mm bearing plus 1/2" thick axle flange and a larger radius to greatly lower the risk of flange breakage.
Sure you can find a cheaper axle in the junkyard or imported from overseas, but remember...You get what you pay for. And in this case, you're going to get much more than you've paid for.
This package includes the axles, 45mm Timken bearings and seals, heavy duty retainer plates, 5/8" circle track studs and our weld-on forged housing ends, specially bored for the 45mm bearings.

Not enough room from the lower control arm bracket to the outside of the hub to keep the tires inside the wheel well. They would be wider by 1 3/4" on each side with floating hubs (even with a 9", a 3 1/2" wider rear track in total).

=====

[lifespeed]

I can see where a true floating axle would require extra space to fit the flange and spindle. A good oversize axle and bearings should work nicely. And you'll keep the extra HP that would be lost to the draggy 9".

[GreekGod]

I picked up my rebuilt 8.8" two days ago. My builder had a few minor problems that held up his work. As you all may be aware "Nothing is really a 'bolt-on'"!

Parking brake with the Wilwood iron rotors wouldn't clear the 5/8-18 studs, so we saved some money and went without the p-brake. The aluminum hat 12.2" diameter 13/16" thick iron vented Wilwood rotors required safety wiring the retainer cap screws.

The O.D. flange taper of the shafts required more machining, and the index center of the flange needed turning to fit the Wilwood hat.

I would like to paint it "Hot" pink, but will probably go with "Rustoleum Cold Galvanize".

Adapting the hydraulic lines should be easy, but since I am losing the ABS function, I may remove all the ABS hardware, and need to add a proportioning valve. Perhaps a new master cylinder is also in order. Might need to disable the ABS light somehow?

The calipers are 4 piston, and will clear 15" wheels. But I now have the problem of finding wheels to fit. I want 10" wide, to fit the 5 on 4.5" pattern and the 5/8" studs. The center hole is over 3" diameter, and wheels need to be 45 degree taper lug seats.


http://www.mercurymarauder.net/gallery/data/500/medium/8_8Rebuild_011.jpg



http://www.mercurymarauder.net/gallery/data/500/medium/8_8Rebuild_009.jpg



http://www.mercurymarauder.net/gallery/data/500/medium/8_8Rebuild_008.jpg



http://www.mercurymarauder.net/gallery/data/500/medium/8_8Rebuild_007.jpg



http://www.mercurymarauder.net/gallery/data/500/medium/8_8Rebuild_006.jpg



http://www.mercurymarauder.net/gallery/data/500/medium/8_8Rebuild_004.jpg



http://www.mercurymarauder.net/gallery/data/500/medium/8_8Rebuild_001.jpg
http://www.mercurymarauder.net/gallery/images/right_sm.png (http://www.mercurymarauder.net/gallery/showphoto.php/photo/23247/title/8-8-rebuild/cat/500)

[Krytin]

Very nice!!!

[lifespeed]

Any update on how this axle bearing and other upgrade worked out? My rebuilt rear end is starting to howl 30K miles after a complete rebuild (except ring and pinion). It would be really nice to have proper tapered roller bearings that could actually hold up to a few thousand miles of use.

[GreekGod]

Any update on how this axle bearing and other upgrade worked out? My rebuilt rear end is starting to howl 30K miles after a complete rebuild (except ring and pinion). It would be really nice to have proper tapered roller bearings that could actually hold up to a few thousand miles of use.

If you have a 2003 or newer, it is complicated to weld on tapered bearing 9" ends, (as far as I know, no one has done it) and retain ABS. I deleted the ABS function by converting to the 33 spline Moser Hobby Stock axle shafts when we went with the 9" bearing ends on my pre-2003 housing.

Only 30K on a complete rebuild means a component failure or improper repair/rebuild. I would expect 100K at a minimum.

==

[lifespeed]

These axles should make it to 100K in theory, but examples of earlier failure are numerous and the aftermarket is awash in axles heat-treated by morons who don't know what they're doing.

I jacked up the car today to confirm the problem is play in the axle/bearing interface. I noted the ABS sensor is very close to the axle tube. So a 9" (or floating) axle end retrofit would at a minimum require larger ABS tone rings to move the sensor further radially from it's current location.

Nothing is ever easy. But I am convinced this axle/bearing thing is futile and I don't want to keep revisiting it.

[GreekGod]

These axles should make it to 100K in theory, but examples of earlier failure are numerous and the aftermarket is awash in axles heat-treated by morons who don't know what they're doing.

I jacked up the car today to confirm the problem is play in the axle/bearing interface. I noted the ABS sensor is very close to the axle tube. So a 9" (or floating) axle end retrofit would at a minimum require larger ABS tone rings to move the sensor further radially from it's current location.

Nothing is ever easy. But I am convinced this axle/bearing thing is futile and I don't want to keep revisiting it.

You can't lump all bearing failures with improper axle contact surface heat treating. I'm sure that many failures are caused by a repeat failure from improper cleaning of a contaminated housing. It happened to me.

Replacing the OEM housing ends requires a degree of re-engineering. A few questions come to mind:

1) Is there space for replacing the ends, and still maintain the same track width?

2) Is there space to narrow the housing, avoid tire/shock damper interference, and allow a wider wheel?

3) Can replacement axles shafts with 9" tapered bearings be equipped with OEM 8.8" ABS rings (9" 31 spline shafts are the same o.d. as 8.8" 31 spline shafts)?

4) Can the tooth counting pick-up sensor be properly located to where the rings turn on new shafts?

5) Do you want to delete ABS, or adapt it to new shafts?

6) Is deleting the parking brake acceptable (I deleted it on my 2000 CVPI)?

7) Would it be practical to use a Sterling axle replacement, in order to retain the Watts link, ABS, and gain 3/4 ton bearings?

I'm sure that a solution can be fabricated, but at what expense, and with how many compromises?

[lifespeed]

You can't lump all bearing failures with improper axle contact surface heat treating. I'm sure that many failures are caused by a repeat failure from improper cleaning of a contaminated housing. It happened to me.

Sure, I just consider it a likely possibility. The rear end and axles were not destroyed and filled with metal when rebuilt. Anything is possible, however.



Replacing the OEM housing ends requires a degree of re-engineering. A few questions come to mind:

1) Is there space for replacing the ends, and still maintain the same track width?

I did not see any width issues, plenty of tube length between the CA brackets and bearings



2) Is there space to narrow the housing, avoid tire/shock damper interference, and allow a wider wheel?

tire/shock clearance is dictated by the CA bracket location. The goal would be to retain factory track width.




3) Cn replacement axles shafts with 9" tapered bearings be equipped with OEM 8.8" ABS rings (9" 31 spline shafts are the same o.d. as 8.8" 31 spline shafts)?

Pretty sure new ABS rings would be needed due to the location of the ABS sensor needing to move outward radially to accommodate the larger bearings. Not to mention axle shaft diameter would be unlikely to match the 31 spline shaft. Likely a custom fabrication, but not an unreasonable part to fab.




4) Can the tooth counting pick-up sensor be properly located to where the rings turn on new shafts?

I think so, new mounting hole location would be needed.



5) Do you want to delete ABS, or adapt it to new shafts?

I want to keep it of course.


6) Is deleting the parking brake acceptable (I deleted it on my 2000 CVPI)?

I would like to keep it, but this seems the most difficult as the larger 9" style end likely could not match the backing plate holes. Maybe a disc brake parking brake, or something similar. Driveline yoke PB? This could be a headache.



7) Would it be practical to use a Sterling axle replacement, in order to retain the Watts link, ABS, and gain 3/4 ton bearings?

Don't know what this is. I was actually planning on looking into floating hubs for race cars.


I'm sure that a solution can be fabricated, but at what expense, and with how many compromises?

I guess I'll find out . . .

Here is a floating hub (https://www.quickperformance.com/mobile/Ford-9-Inch-Grand-National-Floater-Hub-Kit_p_64.html)with the correct bolt pattern. Need to find out more about the required axles and mounting required to implement it.

[GreekGod]

28 and 31 spline 8.8" axles take the same part number/diameter ABS rings

==