Dif's and preloads

[Clark White]

I just put an ARB in my front dif, and after setting everything up and and putting the diff together, I spun the pinion shaft and noticed it seams a bit tight. Everything seams pretty smooth still, it's just a bit stiffer turn then it was before (though its a different carrier and bearings...?). Should I need to tear it all down and redo the carrier bearing preloads? Maybe I over torqued the clam shell (I don't have a torque wrench, so I just torqued them gutentight)? If the preload is set wrong, and it is a bit tight, is that really going to hurt anything?

Thanks!
Clark White

 

[goodtimes]

You say you "set everything up"....did you go through all the pinion depth, back lash, checking the pattern, etc?

A few different things can cause what you are describing, but I doubt that over-tightening the housing bolts will do it.

Have you measured the rolling torque of the pinion? Are you sure it is out of spec? (a fresh set of gears and bearings will have a higher rolling torque than an old set...)

Oh, and to much preload on the pinion bearings can result in a very short life....

 

[2drx4]

Oh, and to much preload on the pinion bearings can result in a very short life....

Why would one touch the pinion to install an ARB?


Carrier bearing preload can be pretty tight and it won't hurt anything. As in, for shimmed carriers if you have to hammer the hell out of the carrier to get it in it will be perfect, for ones with adjusters you can torque them quite tight (30-40ft-lbs, IIRC, but I haven't done one in a long time) and the preload will be fine. The pinion bearings also can be tighter than spec (even NEW spec) and they will often be just dandy as it will break in rapidly and often wind up in mid-range of spec. Often the higher end of the spec will have a breakaway torque that is quite high and will 'seem wrong', but if you measure it with a torque wrench while turning (which you are supposed to) you'll find it to be quite acceptable.

 

[I Leak Oil]

Torque wrenches are cheap. Gears and ARBs are not. Why not just get a wrench and do it right? You'll have an assembly that will last a long time and the piece of mind to go with it. Plus, if you buy the tools, you'll have those for future use also.
If you need an in-lb. wrench I can lend you mine for the cost of shipping it back and forth. It'll probably be just as much to buy one though.
Jason T.

 

[Stumpalump]

This may not end well.

 

[85CUCV]

If you did not pull the pinion you will probably be okay on your gear pattern. If you are using the same gears the pinion depth should be the same. But you should still check the pattern. Like 2drx4 said carrier preload can be run tight as long as you got a good pattern. Even if it is not a gear swap I'd run it 12 miles and let it cool completely before driving again for break in.

You really should use a torque wrench to torque the ring gear bolts and the carrier bearing caps. Use Red Loctite on all hardwear.

What differiental is this?

 

[goodtimes]

Why would one touch the pinion to install an ARB?

Because it is common to change gear ratios at the same time.

OP didn't specify one way or the other.

 

[shawkins]

Do you have one of these to check the PPL?

I'm collecting the tools on ZUK's list in preparation for installing my RD90 and rebuilding the rear third in my '91 4Runner.
http://www.gearinstalls.com/gearinstalltools.htm

 

[I Leak Oil]

This may not end well.

You are correct. If a diff isn't installed correctly it usually doesn't end well.:elkgrin:
Jason T.

 

[Clark White]

Well I tracked down a torque wrench and torqued the ring gear. I am working on the front dif of a Toyota 4Runner. The ARB actually came out of an old axle. For simplifications sake, the old axle (with bad pinion bearing) is dif A, dif on the 4Runner is dif b. So I took the arb out of dif A, leaving the carrier bearings in place, removed ring gear A, put ring gear B on the ARB, put the ARB in the deep side of B, check fit (though I didn't have anything good for marking compound, so it was not exactly scientific), and used the shallow side of the case from A (with air line already drilled and tapped) to close it back up. I checked with the master mechanic at the local Toyota Dealership and he seemed to think that this should be more than good enough since I did not change the ring and pinion, just the carrier (and half the casing already had preload for that carrier).

 

[shawkins]

The carrier bearings should be re-shimmed, you should also need to check the backlash.

Go to Home Depot and buy a torque wrench. Take extra special care to not damage it and keep it looking brand new and when your done, return it. For the rest of the special tools needed, I would get them at Harbor Freight.

Have you read ZUK's site? His site helped me alot to understand this process.
http://www.gearinstalls.com/

 

[gabepari]

Go to Home Depot and buy a torque wrench. Take extra special care to not damage it and keep it looking brand new and when your done, return it.
http://www.gearinstalls.com/

If you can't afford a TW, borrow one. Most of the large auto chains (PepBoys, Autozone, etc...) loan tools. Or find someone that has one and buy them a cold one in exchange.

 

[tdesanto]

...Go to Home Depot and buy a torque wrench. Take extra special care to not damage it and keep it looking brand new and when your [sic] done, return it.

This is deplorable advice.

 

[goodtimes]

This is deplorable advice.

I agree. Far better to go to one of the parts stores with a tool 'loan' program, or borrow one from a friend/neighbor.

 

[kletzenklueffer]

Or just buy one. You need it to torque the bolts on the hubs, the pinion nut, the spindle nuts, etc. It's not like you only need it for the diff. It gets used several times on the front end alone.

Even the cheap bar type shown works and cost maybe $40. I started with one of those, then went to a digital 1/2" drive click type. It doesn't get used a lot, but I'm glad I have it when I need it.