R&P change and weird problem

[pityocamptes]

I was swapping out the front and rear R&P to 4.56 this past week and found a problem with my front Dana 30. It seems that the old carrier was using shim packs for the backlash. I used the old bearings as setup bearings and after installing the R&P and getting the correct tooth pattern and preload, I found that the shims on the carrier were good to go for backlash. I pulled the setup bearings off and pressed the new bearings on.

Carrier would not fit into the housing and was visibly WAY OFF from the inner housing cups. Long story short is I had to remove ALL of the shims on the carrier, used a deadlblow, and only was able to get .0065 - .007 for backlash.

I called Motive and they could not understand why the problem. Anyone know why the old bearings and shims fit and the new ones were tighter than a frogs ass without shims?

Very weird. Thanks!


I should note that the new bearings came in the Motive "Master Kit".

[larboc@hotmail.com]

Do bearings wear? Is that possible?

[stomp-a-jeep]

you got the right carrier right? there is a case break after 3.73's

edit I just read your whole post real good. sounds like bearing wear
to me

[pityocamptes]

The bearings in the front are only 3 years old - thats when I changed them out when I installed the locker. Shit, I knew I should have used the old bearings - too late now.

[pityocamptes]

Originally Posted by stomp-a-jeep

you got the right carrier right? there is a case break after 3.73's

Yes, I made sure of that. I had to buy one for the rear D44 but the front did not need it since it was 3.73. The guy from Motive said it wouldn't really make a difference as the carriers are the same size. What chaps my ass is that the setup bearings and shims fit perfect into the housing with a deadblow. Yet, once I pulled the setups off and pressed the new bearings it wouldn't freakin fit. You could see a huge overlap from the outer race to the inner housing cup - God wouldn't have been able to get that bastard in.

[misterfubar]

The only time I've ever had a problem like that is when i tried to use the wrong bearings. Verify the bearings and races are the same size/number as your old ones.

[pityocamptes]

Originally Posted by misterfubar

The only time I've ever had a problem like that is when i tried to use the wrong bearings. Verify the bearings and races are the same size/number as your old ones.

OK, guess I'll have to yank the carrier out tomorow night - can I get an AMEN on how big of a pain in the ass changing R&P is? I guess when you don't do it often it can take some time...

[CabtopXLC]

I've set up a few R&Ps and never experienced anything like this. When the bearing is pressed on does it look to be the same distance from the "rest" of the carrier as the setup bearings? If not, did one of the shims get folded and crushed when the bearing was put on.

I'd also take a micrometer and measure the setup bearing with the race, front to back, and compare it to the new bearing front to back. Is it possible the wrong bearing was put in the master kit? Can you cross reference the new bearing number to the old?

Just some thoughts.

Brett

[CabtopXLC]

I guess I shouldn't have taken the hour long call with the boss and had 2 gin and tonics while I was in the middle of my repsonse above. But I agree with the potential bearing issure.

Brett

[Binder]

Are you sure the bearings are pressed all of the way onto the carrier? If yes it sounds like you may have the wrong bearings....

In hind sight, if the old bearings were in good shape and good brand bearings you really didn't need to replace them. If the old ones were Timken and the new ones were "never heard of it before" brand I would have used the new ones for setups and reused the Timkens...

[pityocamptes]

The new ones are Timkin also. I also checked and rechecked to make sure they were all the down on the sleeve and tight up against the shoulder.

I took last night off to enjoy a grunge metal concert - will start up again today after work. I might buy a new set of bearings and races on the way home so that if the "new" ones are wrong or bad I don't have to postpone the work 'till tomorrow. I've been working on this for a couple of weeks now between school and work and am reaching the burn out stage.

[pityocamptes]

Could this be the problem?!?!?!?



Motive sent out:

Bearing: LM501349
ID - 1.6250
width - .7800

Race: LM501314
OD - 2.8910
width - .8437




Timkens catalog says this:

Bearing: LM501349
ID - 1.6250
width - .7800

Race: LM501311
OD - 2.8910
width .9060

[REDDMANIAC]

some races are also thicker, out the old bearing & race together and compare with the new. (maybe this is what you mean by thicker)

[guidolyons]

I'd say that .0623 would make a huge difference, and would explain your problem. Looks like you need to set up the gears again. That bearing number could very well be correct for the application, and be with in the manufacturing tolerances, unfortunately it's they aren;t the same as the ones you used to set up.

I would get a new set of bearings since you have pulled those on and off a few times already just to make sure the cage didn't get bent in the process.

EDIT: I see you already got a new set of bearings...nevermind.