Issue after 3rd member rebuild (1 Viewer)

[kcustom73]

So got my hands on a full float axle from a 78 FJ45. The axle was a little ruff but could easily be rebuilt. So during the rebuild I decided to have the 3rd member rebuilt with new seals and bearing and also have the drive flange swapped out to match the drive pattern from the splitcase I have in the 40.

So I dropped off the 3rd member and a rebuild kit I got from Cruiser Outfitters and dropped it off at a locale shopped that have a good reputation for this kind of project. Picked it up last night and being in a rush between work and daycare didn't test it before bringing it home. Got in the shop last night to put a little paint on the 3rd member before bolting it back up and decided to give the drive flange a spin. What I found was a really hard to spin by hand drive flange. Compare to other 3rd members I have in the shop, I can barely spin it one handed.

I'm thinking that the pinion nut it too tight. Can I just back it off a bit until everything things moved freely and call it good or do I have to bring it back to the shop and have them replace the crush sleeve and re-tighten properly?

 

[pb4ugo]

It should not spin as freely as a used 3rd. It should be stiff with proper setup and new bearings. Don't loosen the nut. I'd take it back and have them check the pre load. If there's too much preload, they will have to install another crush sleeve.

 

[B y r o n]

Unless there is a process I'm not aware of there is no way to recheck the preload. That means a partial disassembly and new crush sleeve would need to be installed. Talk to the shop and if they say it went together right the first time then there is a good chance with their reputation it is right. I assume they offer some type of warranty? If you're still not sure then my guess it is going to cost you the new sleeve, a new seal and the labor to install it. You just have to decide how comfortable or un-comfortable you are with it and them.

 

[Tancruiser]

How far did you drive it? If it’s too tight it’ll get pretty warm pretty quickly go for a ride crawl under and see how warm the housing is.

 

[kcustom73]

Tancruiser, 3rd member is still sitting on the workbench so can't really tell you if it's getting hot.

I'll try and take a quick video tonight when I'm in the shop and post it here. Might give you guys a better idea.

 

[RustyNailJustin]

With new pinion bearings, you should have 12 to 15 inch pounds of preload on the pinion. When you spin the flange you are feeling carrier bearing preload too but you should be able to spin with one hand very easy.
Ask them to check their setup and try again.

 

[whitey45]

Check the backlash too, could be tight, should spin very smooth with slight resistance. Did they check the contact pattern? It is a very precise setup, so double check everything.

 

[Mace]

Yeah, shouldn't be that hard to turn. Take it back to them

 

[RustyNailJustin]

Good p

Check the backlash too, could be tight, should spin very smooth with slight resistance. Did they check the contact pattern? It is a very precise setup, so double check everything.

Also a good point, could be backlash or pinion depth. In theory they pulled the pinion bearings and put the same size shim stack in there but could have got messed up.

 

[reddingcruiser]

It’ll wear in

 

[Cruiserdrew]

Wait. Don't speculate here. Post up pics of the gear paint, and the preload values. With a fresh rebuild there is significant preload that's normal. It should turn with firm pressure. If it truly "tight" something is wrong.

What ever you do, don't just "back off the nut". The tightness of the nut is NOT your problem. It's deeper than that. And if it was your problem, backing it off, will not solve it. It will just make it destroy itself from no preload on the bearings.

Do not install and put under load until you are happy with the set up.

See the @gearinstalls.com website to get an idea of what's involved and what's at stake.

Toyota Gear Install Harrop

 

[kcustom73]

Took a look at it some more tonight. Contact pattern looks good. Put a torque wrench on the drive flange and it's taking 40 in/lbs to get it to move (was 43 in/lbs before I put a little gear oil on the pinion and spun it by hand a bit)

 

[SuperDuperCruizer]

I had to re-do a partially rebuilt differential somebody else started and walked away from. The pinion was binding up/not turning freely by hand as you’re describing. The differential I was dealing with did not use a crush sleeve to set the pre-load for the pinion. The pinion has a washer and shim to set the pre-load and then the depth is adjusted using shims underneath the inner pinion bearing race (see photos). After disassembling the pinion I noticed the original shim behind the new bearing race was a different inner diameter and was rubbing against the bearing pressed on the pinion pictured below. I removed the bearing race, read the thickness markings printed on the shim and double checked it with my calipers. The rebuild kit came with a shim pack having shims with inner diameters matching the bearing race of the rebuild kit. I used the corresponding shims from the rebuild kit and reassembled the pinion resulting in the correct preload/no binding.

If this is what happened to your rebuild, then the shop is basically going to need to redo quite a bit. Once the pinion depth and bearing preload is set; then the carrier needs to be setup to mesh the gears properly (backlash/contact pattern).

 

[kcustom73]

I'm finally looking at this again. So I decided not to bring it back to the shop. If they messed it up once, who says what they are going to do the second time.

So trying to figure out the root cause of the stiffness, I took the carrier out leaving me with just the pinion installed. I put my torque wrench on and measured the pinion pre-load to a consistent 25 in/lbs to the pinion to spin. According to the FSM is should be between ~16 to 22 in/lbs. What I figure has happened is that during the rebuild the original ring was to rusted to reuse (the full float axle had sat outdoors for years and water got into the diff) so I supplied the rebuild shop with a spare r&p I had. I wondering if when they put it back together with the old shims and didn't recheck the preload...

Now not wanting to have to pull the pinion bearing to many times, is there a way of knowing what shim to use to get the pre-load back between the recommended values?

 

[Cruiserdrew]

Pinion preload should be more like 10-12. Carrier preload adds another 10 or so.

You new Ring and pinion has a crush sleeve or a solid spacer? Too bad the 78 had to be tossed because that year, and that year only was fine spline, with the solid spacer built into the pinion itself. Before 78 was coarse spline pinion and after required a crush sleeve.

Anyway, no simple way to do this. And it will require multiple assemble/disassemble steps, including pressing the big pinion bearing on and off without damage.

I really recommend you read some installs on the gear install website. Here is may install, at gearinstalls.com for example:
Harrop elocker FJ60 456 Nitro gear install

 

[Rusty 72]

Has your torque wrench been calibrated?

 

[SuperDuperCruizer]

Just to clarify: I use a torque wrench to tighten the pinion nut and I use a torque meter to check the preload of the pinion bearings.

You tighten the pinion nut according to specs. using something to hold/keep the pinion from spinning. I have a companion flange tool to hold the pinion while I tighten the nut but there are suitable substitutes for this purpose. You check the pre-load after the the pinion nut is torqued to specs. If the pre-load is not within specs; you need to add/remove a shim on the pinion. You should not be setting up the ring gear till the pinion is setup properly.

A crush sleeve is a different process than what I've described.

 

[kcustom73]

So I finished taking apart the pinion last night. I pulled the large bearing to find no shims under the bearing. If my understanding is correct, the shims under the large pinion bearing is to set depth/contact with the ring.

I think I will get a new bearing (damaged it while removing it) and reinstall with no shims (the contact pattern looked good after the rebuild)

I also found this great post that is helping me understand the whole process

Ring gear backlash question

I will use this information to adjust preload and then go from there. Any major flaws with this thinking?

 

[Mace]

For the bigger bearing on the pinion, the shims go between the case and the bearing race, not the bearing and the pinion. The smaller bearing (further away from the pinion head, near the flange) has a crush sleeve or shims to adjust preload.

You might want to look into the whole diff setup a bit more.

 

[SuperDuperCruizer]

Yes; the bearing race installed in the differential housing should have a shim underneath it. This sets the depth of the pinion. The shims underneath the flange set bearing pre-load. The pinion nut will compress as much as the shim underneath the flange will allow but the pinion nut is not what sets the bearing pre-load.

The differentials using a crush sleeve are a bit different.