New Gears Gone Bad

[maraudernkc]

I just had new Ford Motorsport 4:10 Gears installed by a SAE good friend of mine two weeks ago. I went out of town over the weekend and get out about 300 miles and I start hearing this loud howling noise. I knew it was the rear end. I called my friend and he said that the back lash and everything was perfect.

Stopped at a Ford dealer and they said they thought it was the Pinion bearing. He said take it back to my dealer and they should replace everything with new parts.

Should I take it to my dealer and tell them about the gears and see what they say or should I take it back to my friend and just replace the bearings, if that is the problem?

The MM did make it back 300 miles. I was waiting for it to lock up but it did not!

Greg

[MarauderMark]

I went threw that problem. i had someone else (an sae as well) install my 1st set of 4:10s that only lasted a few months then the teeth broke.i had the dealer install the next set and when they opened up the rear they said they were improperly installed.Maybe all you need is a bearing did he reuse the old one or put in a new bearing?

[Patrick]

Not sure if this helps but I already have talked to my dealership for the gears. If I have a problem they will address it. Warrenty they will work it out. I would take it to the dealership, If you have a working relationship with. And let them fix it. I am going to let them do my gears and Dennis will do the tune and Later the S/C. Much Later on the S/C. Just my :twocents:

[JFB]

Did your friend add friction modifier to the rear end lube? It's a must!

[FiveO]

Did your friend add friction modifier to the rear end lube? It's a must!


My first thought too....I know without it you'd lose the posi.

Not sure if not adding it would cause these types of problems....anyone else know?

[SergntMac]

I don't mean to talk bad about anyone's wrench, but there's no way to avoid sounding like I am here. That's not my intent.

I wouldn't say anything at all if I had not gone through this myself. In June of '03, I blew the rear end apart so bad, I had to replace everything except the housing. One ring bolt almost punctured the cover, and the rest trashed internals. I have pics in a .zip file, e-me at SergntMac@aol.com

IMHO, it's not just a gear swap. There is tremendous power delivered against all these components, and when you're into your WOT power, it's all pushing straight out the back. Anything misaligned, or, under torqued will be the weak spot. Like other systems in the power train, the OEM stuff takes a lot of abuse until you disturb it, and once you do, you have to button up things right, or it will come apart.

A responsible build includes case hardened ring bolts (what blew on mine) pinion and carrier shims, new bearings, races, crush sleeve and seals all around. This adds about 150 bucks to the parts list, but that's cheaper than doing it over. I'd also add the stud kit and girdle while it's open.

The FRP catalogue has 8.8 install kits at three levels, M-4210-A, B, or C. The C kit has all you need in one kit for a proper setup. The stud kit is M-4034-A, and the girdle is M-4033-G, though any of the popular girdles offered here will work as well.

I don't mean to sound preachy on you Greg, but for the benefit of other members considering a gear change, this is a "you need to hear this" opportunity. Wishing you the best in your rebuild.

[Agent M79]

Did your friend add friction modifier to the rear end lube? It's a must!.

Yes, it is.

The symptom you describe though is not brought on by the lack of friction modifier.

Lack of friction modifier presents itself and a pulsing or thrumming noise while turning a corner. I was told it was the clutch packs dealing with turning the rear wheels at different speeds.

Further, I was told it was not a very serious issue. I added a an uprated girdle and stud kit and when I did that, I had them add the friction modifier and the noise went away.

[BillyGman]

If he didn't have the friction modifier, than he would've heard a lot of chattering around turns, but I don't believe that it would effect the ring & pinion gears. However, I'm sure it would eventually beat-up the limited slip clutches. What it sounds like to me is that the pinion depth wasn't set correctly, or the old pinion bearing was used which isn't a good practice. When the old pinion bearing is pressed off of the pinion shaft using the clam shell tool (which BTW, is the only way to remove it) the cage of the pinion bearing is usually distorted slightly.

So if the bearing isn't replaced, it may very well cause problems later on. Another thing is also that the proper pinion pre-load must be set which has to be measured w/an inch pounds torque wrench, and needs to be set to 25 in/lbs for new bearings. All of these things must be tended to, and not simply the backlash alone. I replaced the gears in my Marauder, and I have 15,000 miles on the new set now, and they're fine. If you ever perform this yourself, you need to pay attention to these things, and if you have someone else perfrom the task other than a professional garage, then you need to watch them to make sure they tend to the things I've mentioned. One other thing...... the ring gear bolts that come w/the ring & pinion gear set should be used during the gear installation, and permanent loc-tite thread locker (red) should always be used on the ring gear bolts, and they need to be torqued to 65-77 ft/lbs.

[Dennis Reinhart]

I just had new Ford Motorsport 4:10 Gears installed by a SAE good friend of mine two weeks ago. I went out of town over the weekend and get out about 300 miles and I start hearing this loud howling noise. I knew it was the rear end. I called my friend and he said that the back lash and everything was perfect.

Stopped at a Ford dealer and they said they thought it was the Pinion bearing. He said take it back to my dealer and they should replace everything with new parts.

Should I take it to my dealer and tell them about the gears and see what they say or should I take it back to my friend and just replace the bearings, if that is the problem?

The MM did make it back 300 miles. I was waiting for it to lock up but it did not!

Greg

If installed properly you should not have any problems, the Ford 8.8 is a easy rear end to set up if you have the proper tools. I use the Ford Rotunda tool and its very easy, in your case if you had bearing failure the gears should be fine with new bearings, any compatent speed shop the do a lot of Fords should be able to do this in there sleep, if not see if you can find a Ford mechanic to do this on the side for you.

http://www.marauder57.com/Reinhart%20SC%20Banner%201.gif

[maraudernkc]

The car had 800 miles. He used the orginal bearinf and Ford Motorsports gears. He is going to open her up Tuesday night and see what the heck is going on.




I went threw that problem. i had someone else (an sae as well) install my 1st set of 4:10s that only lasted a few months then the teeth broke.i had the dealer install the next set and when they opened up the rear they said they were improperly installed.Maybe all you need is a bearing did he reuse the old one or put in a new bearing?

[maraudernkc]

Ye she did add the friction modifier.




Did your friend add friction modifier to the rear end lube? It's a must!

[maraudernkc]

Sergnt Mac, The gears were put in when the car had 800 miles. My SAE mechanic friend said that all the bearings looked perfect therfore he did not put new ones in. Should he have put new bearings in with only 800 miles on the odometer?




I don't mean to talk bad about anyone's wrench, but there's no way to avoid sounding like I am here. That's not my intent.

I wouldn't say anything at all if I had not gone through this myself. In June of '03, I blew the rear end apart so bad, I had to replace everything except the housing. One ring bolt almost punctured the cover, and the rest trashed internals. I have pics in a .zip file, e-me at SergntMac@aol.com

IMHO, it's not just a gear swap. There is tremendous power delivered against all these components, and when you're into your WOT power, it's all pushing straight out the back. Anything misaligned, or, under torqued will be the weak spot. Like other systems in the power train, the OEM stuff takes a lot of abuse until you disturb it, and once you do, you have to button up things right, or it will come apart.

A responsible build includes case hardened ring bolts (what blew on mine) pinion and carrier shims, new bearings, races, crush sleeve and seals all around. This adds about 150 bucks to the parts list, but that's cheaper than doing it over. I'd also add the stud kit and girdle while it's open.

The FRP catalogue has 8.8 install kits at three levels, M-4210-A, B, or C. The C kit has all you need in one kit for a proper setup. The stud kit is M-4034-A, and the girdle is M-4033-G, though any of the popular girdles offered here will work as well.

I don't mean to sound preachy on you Greg, but for the benefit of other members considering a gear change, this is a "you need to hear this" opportunity. Wishing you the best in your rebuild.

[BillyGman]

The gears were put in when the car had 800 miles. My SAE mechanic friend said that all the bearings looked perfect therfore he did not put new ones in. Should he have put new bearings in with only 800 miles on the odometer?I wouldn't use the old pinion beatings since the clamshell tool that's used to press-off the large pinion bearing from the pinion shaft tends to spread apart the bearing cage. However, if someone insists on cutting corners by using the original bearings, then it's important to check the pre-load on the pionion bearings w/an inch/pounds torque wrench after the ring gear and differential are reomoved, and BEFORE the pinion is removed. Because when the new pinion gear is installed, the pre-load on the old pinion bearings needs to be set to the same in/LBS setting that it was before it was removed. otherwise, pre-mature pinion bearing failure is very possible. So if that wasn't done, then the mechanic in question failed.

[FordNut]

Sergnt Mac, The gears were put in when the car had 800 miles. My SAE mechanic friend said that all the bearings looked perfect therfore he did not put new ones in. Should he have put new bearings in with only 800 miles on the odometer?
It is common for the pinion bearing to be damaged in the process of removing it. The rest of the bearings can be re-used but a new pinion bearing and seal should be used.

[TheDealer]

I too agree. You should NEVER press off an old pinion brg. and then press it onto the new pinion. It will distort the brg. Not to bad mouth your wrench but I can't believe anyone knowing anything would do this.

[SergntMac]

SergntMac, The gears were put in when the car had 800 miles. My SAE mechanic friend said that all the bearings looked perfect therfore he did not put new ones in. Should he have put new bearings in with only 800 miles on the odometer?
We can collect opinions on this until the cows come home, Greg, and not find agreement. IMHO, yes, the bearings should have been replaced. Some will say this is overkill, but are you not rebuilding your rear end again?

It is common for the pinion bearing to be damaged in the process of removing it. The rest of the bearings can be re-used but a new pinion bearing and seal should be used.
The FRP install kit I mentioned above lists for 119.00 and it includes everything you need in Ford Racing parts for a professional install. This may add a few bucks to the labor charge, so, let's round it out to 150 bucks tacked on to a gear upgrade budget, and look again.

My rear end broke when I was into WOT and a ring bolt got loose. It bounced around and tore up everything, busted the ring gear and the differential. My rebuild cost ran over 1500 bucks in parts and labor, and out of my pocket too, no warranty coverage. The rear end that broke, wasn't built by Kenny Brown, so, it's not his shortcut that failed. Therefore, IMHO, whomever thought "things looked okay" when the first set of 4:10s were installed in my MM, cost me a chunk of change down the road. This isn't my opinion, it's a fact, draw your own conclusions.

In other threads here, we have heard from members who paid as little as 200 bucks, and as much as 800 bucks for a gear change. You get what you pay for. The skill needed to make a gear change is not quantum physics, but you shouldn't let any wrench of any professional achievement work on your MM, if he isn't looking down your ownership road in your best interests. It's not a matter of mechanical skill, but a matter of forward thinking on your behalf.

My advice to anyone considering any gear change, is to spend the extra money and do the job once. This includes adding optional stud kit and girdle. Though you don't plan on it today, in six months you may want to supercharge, or go racing. Wouldn't that be a lot more fun knowing that everything in the rear end is ready for more fun?

[BillyGman]

The skill needed to make a gear change is not quantum physics, but you shouldn't let any wrench of any professional achievement work on your MM, if he isn't looking down your ownership road in your best interests. It's not a matter of mechanical skill, but a matter of forward thinking on your behalf.

MAC is passionate about this subject because of the trouble he had w/the rear end of his Marauder, and I commend him for his concern, and for him caring enough about his fellow Marauder owners to give them a stern warning here. And I happen to agree w/him on the above quote. I've performed a gear swap myself on my Marauder twice, and both times were successful. The first time I swaped the stock 3.55 ratio for a new set of 4.10's, and after putting 2,000 miles on them after the installation w/out any problems, I decided that 4.10's still weren't providing me w/the acceleration I wanted, so I performed a second gear change myself to install the 4.56 ratio gears. This all took place last year, which was before I ever seriously considered S/Cing my car.

But the main point that I want to make here, is what MAC is saying in the above quote is absolutely correct, and accurate. It doesn't take a brain surgeon to perform a gear swap, but it is a big job, and it does take either a lot of experience, or the person performing it to have done their homework forward & backwards BIG TIME!!! He should have your best interest in mind, and care enough about your car to avoid cutting corners that aren't good to be cutting. Anyone can perform a gear swap, but to do it correctly, so there won't be major problems about 500 miles down the road, does require attention to detail, and proper procedure on the part of the mechanic performing the installation. In the case of MAC's failed ring gear, my guess is that either the ring gear bolts weren't torqued properly (if at all!!), or the permanent LOC-TITE thread Locker (RED) that I spoke of in a previous post wasn't used on the bolt threads. And that needs to be done, among the other things that I previously mentioned.

[maraudernkc]

Gman, thanks for the insight. My friend said he did do all that except for putting in new bearings. The car only had 800 miles and he said the bearings looked perfect. He is going to pull it apart on Tuesday.

My Merc. dealer did say if the gears were installed properly that they would take care of it under warranty. Thanks for the insight.

Greg


If he didn't have the friction modifier, than he would've heard a lot of chattering around turns, but I don't believe that it would effect the ring & pinion gears. However, I'm sure it would eventually beat-up the limited slip clutches. What it sounds like to me is that the pinion depth wasn't set correctly, or the old pinion bearing was used which isn't a good practice. When the old pinion bearing is pressed off of the pinion shaft using the clam shell tool (which BTW, is the only way to remove it) the cage of the pinion bearing is usually distorted slightly.

So if the bearing isn't replaced, it may very well cause problems later on. Another thing is also that the proper pinion pre-load must be set which has to be measured w/an inch pounds torque wrench, and needs to be set to 25 in/lbs for new bearings. All of these things must be tended to, and not simply the backlash alone. I replaced the gears in my Marauder, and I have 15,000 miles on the new set now, and they're fine. If you ever perform this yourself, you need to pay attention to these things, and if you have someone else perfrom the task other than a professional garage, then you need to watch them to make sure they tend to the things I've mentioned. One other thing...... the ring gear bolts that come w/the ring & pinion gear set should be used during the gear installation, and permanent loc-tite thread locker (red) should always be used on the ring gear bolts, and they need to be torqued to 65-77 ft/lbs.

[BillyGman]

you're very welcome. Any time!! Let us know how things work out for you in this matter.

[MarauderMark]

. dealer did say if the gears were installed properly that they would take care of it under warranty. Thanks for the insight.

Greg


Wish i had a dealer like that .Or you can beat that if you took it to the dealer they would've said that they were improperly installed just so you can pay.At least that what my dealer is like...

[maraudernkc]

It was the Pinion bearing that was bad. My mechanic is replacing all the beaings.

Thanks for all the advise.

[BillyGman]

Like I've previously stated in this thread, it isn't a good practice to use the old pinion bearing since the bearing cage will often be slightly damaged while the bearing is being pressed off of the old pinion regardless of whatever mileage there is on it. And if you're going to replace the large pinion bearing (that's the one that gets pressed off) then you should replace the small one also since the degree of pre-load that will be used will be exerted on both the large and small pinion bearings, and the pre-load spec for new bearings is different than the one for used bearings. So if you use one used pinion bearing, and one new one, then the degree of pre-load will either be too much for the used bearing, or not enough for the new one. When the bearings don't have many miles on them, and they look good, then it's fine to leave the differential bearings on w/out replacing them since they don't have to be pressed off just to peform a gear swap like the large pinion bearing does.