4.10 install break-in ???

[warren]

Talked to a shop today for 4.10's
and he said------ use syn. oil only and
2hr's to install and the break-in is
for the 1st. 100 miles
Drive 15minutes only and wait 1/2 hr.
Drive another 15 minutes, wait 1/2 hr. etc.
Do this for 100 miles.

Have any of you heard of this.
Do any of you have a different break-in
program for the rear gears???

Thanks,

Warren B

[TAF]

I think that is :bs:...

Some agree...others don't...

read this thread for all the advice you ever wanted to know.

http://www.mercurymarauder.net/forums/showthread.php?s=&threadid=3630&highlight=break+in+for+gears

[Mikeenh]

After Reinhart installed my 4:10's I had a 4 hour drive to where I had to go. I did it non stop and ran it up to 125 in third on the way. I did use synthetic rear oil. Thousands of miles later my rear is fine :D

[amerikan]

The shop in which i got my gearing installed said 500 miles untill breakin period is over. However, after posting a thread on MM.net everyone disagreed and i said the H#LL with the breakin and only went up to 100miles.. the car is just fine.

[BillyGman]

the "break in" period for the ring & pinion gears is merely to prevent the possibility of prolonged and/or excessive heat bulid up in the rear. When gears are new, you don't want to heat them up for an excessive or prolonged amount of time which BTW, can happen if you go for a 2 hour drive initially after the installation(especially if new bearings were also installed).
Remember that ring & pinion gears aren't all that hard. Sure they go through some heat treating during the manufacturing process, but they're intended to be pliable enough for the teeth to actually flex a little under high torque conditions. If the manufacture was to make the gears too hard, then they would also be too brittle, and end up cracking. So by allowing a cool-down fase to take place between 5-10 mile leasure drives, it helps to temper the gear material a bit......

[SergntMac]

Well, I think you ought to take a clue from your new car beak in program, those gears are brand new too, eh? Would you drive your brand new MM for 15 min and wait a half hour to drive another 15 min?

[JohnnyB]

After the speed shop installed my gears back in March '03, I had a 45 minute drive home..... all highway. I just drove normally. No problems.

[BillyGman]

Originally posted by SergntMac
Well, I think you ought to take a clue from your new car beak in program, those gears are brand new too, eh? Would you drive your brand new MM for 15 min and wait a half hour to drive another 15 min?

That's a thought provoking point, however it also depends to a certain degree what gear ratio you change to. If you go lower(meaning numericaly higher), then the pinion gear as well as the two bearings it rides on will have a greater tendency to heat up since they're turning faster and more total revolutions per each revolution of the axles. For instance the stock gearing which happens to be a 3.55:1 ratio for the MM, will have the drive shaft, pinion gear, and pinion bearings turning 3.55 revolutions per each rev of the axles, whereas a 4.10 gear set will obviously have the driveshaft and pinion gear turning 4.10 revs per each turn of the axles. That might not sound like a big deal, but you have to keep in mind that the wheel is turning thousands of times every day that you drive it. So the speed of the pinion and it's bearings will be much greater w/the lower gear set.And that will have the potential to generate more heat. But ofcourse if you were to go to a higher gear ratio(Lower numericaly) such as 3.27:1 or 2.73:1, then you wouldn't have to be too concerned about that. The stock Marauder gearing ratio of 3.55:1 isn't anything that can possibly be considered extreme, from a performance standpoint, or an engineering standpoint........

[Marauder57]

When Dennis put in my 4.10's he said break in is about 150 miles....so he said vary the speed and don't use Cruise control.....that was basically my trip home......all is well. And he put Mobil 1 syn in the gears.....

[BillyGman]

here is that you can do whatever you want w/your car, and you might be okay, and you might not. But as for me, when I do a gear change(and I just did one myself to 4.56 gears in my Marauder) I'm going to take the time to go through a brief break-in period because I think there's logic in doing that. Especially with a performance ratio. And even though I haven't used Richmond gears in my MM, I do have their installation video, and they tell you to go through a break-in period, and I'd like to think that the manufacturing company of performance gears such as Richmond know what they're talking about.......

[WolfeBros]

I don't know what the Richmond break in period is but I can tell you that the drive it 15 minutes then park it for 30 minutes is the most ridiculous thing I have ever heard. Dennis's recommendation makes sense and is not extreme. (much like breaking in a new car......good sense prevails usually)

[BillyGman]

I guess in your eyes the opinions and/or theories of the most major manufacturing company of gears and Transmissioins are "ridiculous". But hey, you're entitled to your opinion guy just like all of us....peace

[WolfeBros]

Billy I have been playing with muscle cars and racing for over 36 years. And yes I turn my own wrenches. If you are telling me that all the major gear and transmission people are saying to drive it for 15 minutes and then wait 30 minutes. I would say that is a bit extreme. And it is also the first time in 36 years I would have ever heard a recommendation like that. And thats not just my opinion it is based on my experience as well. It doesn't mean your wrong and I am right or vice versa. I agree on break in periods and I am usually more conservative than most. But 15 on and 30 off ?

[BillyGman]

agree w/you on this one Wolfe, I do appreciate your intelligent and mature response. I know that a thread like this one where we have contrasting opinions can have the potential for an ugly argument to erupt that would include personal attacks, and I'm really not into that, and it seems to me that you aren't either. So that's really cool. I respect you for being one of us who do atleast most of our own mechanical work. So you must understand my point in one of my previous posts concerning the higher bearing and pinion speeds of gear sets that are of a numericaly higher ratio. Ya know how the drag that the pre-load puts on a new pinion bearing? I'm sure that this coupled w/the performance ratio can generate more heat.After awhile, those pinion bearings will loosen up a bit and the drag will not even be half of what it originaly was when you've installed them. I know that because I've checked w/a dial torque wrench the amount of drag or preload on pinion bearings that merely had 1500 miles on them, and it was already considerably less than when they were installed. And bearing races are a lot harder than the ring and pinion gears are. Like I said, I'm not gonna claim to be an expert in metallurgey, but I know that Ring& pinions are designed a bit softer than other steel [parts so that the teeth will flex a little. But maybe we will just have to agree to disagree on this one Wolfe, and the rest of our readres can decide who's theory they want to believe. Again, thanx for your response, and your opinions even though I don't agree......

[WolfeBros]

Billy I actually think we are closer to agreement than disagreement on this one. I appreciate your input and your posts.
Next round is on me if you get to Ennis.
:beer:

[BillyGman]

cool........

[Bigdogjim]

Very good read guys. That why I love this site!

All the info you need and then some!

[warren]

Thanks to all of you !!!

I have checked several Mfg's. and they all
suggest a cooling down period after 10 to
20 miles. Richmond says go 10 miles and
stop for 30min. Do this 2 to 3 times.
Check out ---
http://www.richmondgear.com/01instructions.html

Thanks again for all of your fine input.
This web-site is NO.1, Logan.

Thanks, Warren B.:)

[Meteorite]

I just got my Marauder 2 days ago (used, 6600 miles). It definitely does scream out for a higher gear ... so now I'm thinking about 4.10s.

2 questions:

(1) What kind of revs are you guys seeing with these gears at, say, 80mph?

(2) If I need warranty service, am I likely to run into dealers that consider the gears to have voided any part of the warranty?

Thanks,
Paul

[2003 MIB]

I don't know 80mph. At 70 it's 430 more. Where are you. Paul?We have a mod. friendly dealer in Dallas.

[Meteorite]

I'm in Michigan, nnear Detroit. I don't know about the service guys, but the used car dealer guy didn't seem to know squat about cars.

Yeah, I suppose I need to hunt down a mod-friendly dealership.

[2003 MIB]

That's my advice, for what it's worth...There are quite a few folks from your part of the world on this site. Somebody's gotta have the name of a mod. friendly dealer. Please.

[BillyGman]

w/4.10 gears at 80 MPH you'll be reving at 2800 RPM in overdrive, and 3900RPM in 3rd gear;)

[Hemlock]

MY 4.10s HAVE 32,000 MILES W/O BREAKIN , NO PROBLEMS .

[Meteorite]

Thanks 2003 MIB & BillyGman ...

That's just the info I was looking for.
4.10 sounds perfect.

[Adem]

I think that time delay thing has something to do with "better safe than sorry." In none of my cars have i ever done that after putting gears in, and ive never had a problem. Also, race cars never have a break in period, and they never have problems. As long as everything is set to the correct tolerances, the heating and cooling shouldn't affect it very much.

[SergntMac]

Originally posted by BillyGman
w/4.10 gears at 80 MPH you'll be reving at 2800 RPM in overdrive, and 3900RPM in 3rd gear;)

Odd...I read 2500 RPM with OD on, and 3500 with it off.

I don't trust the factory gauges much at all...

[BillyGman]

that's close to what my tach read at 70MPH when I had the 4.10's in(3rd gear-3450RPM, and O/D-2400RPM). But he was asking about 80MPH. Did you read that right?