Differential work. Recommendations?

2001 QC 4x4 2500 V8 with 188,800 miles

Was changing the fluid in my rear differential today and noticed a small chunk of material missing from one of the teeth in the driver side axle shaft gear. I haven't noticed any problems and for the time being am going to proceed with just the fluid change. However, I'm also going to go ahead and make plans to effect a repair to the damaged part and would like to have input from anyone experienced with this on anything additional I should go ahead and do.

Let me also state that it appears that some fluid leaked out on my trip to the beach this weekend and there was a good bit all over the boat as well as the back of the truck and undercarriage. As for amount that was removed, the fluid was approximately 3/4" low so there was no issue with being run without fluid.

Reply to
Carolina Watercraft Works
Loading thread data ...

Try to isolate where the leak is. It could get suddenly worse, and leave you 'high and dry' so to speak.

As to fixing it, did you find the 'chunk' that came out of the tooth? And how big was it? (A picture would be excellent). It is possible you could drive forever liek it is, or maybe only make it another 10 miles.

Reply to
PeterD

The leak came from the seal. It appears that when it (oil) leaked it was flung up onto the bottom of the bed and everything. I was already planning on taking a picture when I get back under today.

I hear ya on the time to possible failure but the piece missing doesn't seem to be that bad. There were the obvious metal slivers on the magnet but I did not look for a larger chunk yet as I was waiting until today to get back under there. Will let you guys know what I find.

Reply to
Carolina Watercraft Works

If it's just the side gear you're looking to replace, and you have an open differential (not limited slip), the procedure is pretty simple:

Remove the cover, drain the gear oil. Jack up one tire, and put the transmission in neutral. Turn the tire, or the driveshaft, to turn the gear case so you can get to the cross shaft retaining pin (little pin w/ a 1/4" or 5/16" hex head that holds the cross shaft in place). Remove the pin, then remove the cross shaft (probably gotta move the diff case back and forth to get the pin out). Now turn the wheel or driveshaft, and the diff will spit out the spider gears. Don't lose the thrust washers. Now you can remove the side gear(s) (again, don't lose the thrust washers) and put new ones in. There should be enough room to remove the side gear without pulling the axle. If not, unbolt the axle at the flange (8 bolts) and slide it out slightly.

Re-assembly is the opposite - the only trick is getting the spiders back in place so that they're aligned with the hole for the cross shaft. To do so, first turn the driveshaft to align the gear case with the cross shaft hole at the top. Next put the first spider gear between the side gears directly in front of you (would be the 3 o'clock position if looked at it from the side). Then turn the wheel so that the spider gear rotates a full 180 degrees. Put the other spider in the same way you did the first, and then roll the wheel in the other direction so the spiders align with the cross shaft. Rotate the driveshaft to bring the cross shaft hole in to view, and install the cross shaft. If everything's not in alignment, turn the wheel to bring a spider gear back to the front, and adjust it's position. Trust me, this will all make sense when you're playing with it.

Once the cross shaft is back in, re-install the pin, tighten it (not a lot - it can break... loc-tite is good here), replace the gasket and cover, re-fill, and you're good.

FYI - a whole set of replacement side/spider gears should be around $100 - $120, so an individual side gear could be had for around 25% of that, I would think (never bought just one - always did them as a set). They're not a matched set like a R&P set, so no issue with just replacing the busted piece.

Now, if you have a limited slip, it's still doable - but a bit more involved. The carrier needs to come out, be disassembled, put back together, and re-installed. I'm hoping you have an open diff :)

Reply to
Tom Lawrence

Nope, limited slip. I sam a few very small chunks missing from the other side so I'm going to plan on doing both at the same time. Do you recommend replacing the clutch plates as well since I'm going in with both feet? Bearings? I will of course be replacing the seal also.

Reply to
Carolina Watercraft Works

Might as well.

The pinion seal? Are you planning on replacing it without removing the pinion? You can do this, and it won't change the setup - just re-torque the pinion nut to about 200ft.lbs., and Loc-tite it. That won't be enough torque to compress the crush sleeve any more. However, if you're yanking the carrier out, you can just measure the pinion preload, and torque the pinion nut until you achieve between 10 and 20 in. lbs. (the spec for used bearings... 25-45 in.lbs. if you use new pinion bearings)

As to yanking the diff... you're going to need a case spreader, and a bearing puller/hydraulic press to change the bearings. If the bearings aren't worn, I'd leave them alone.

So, to get the diff out - pull the axle shafts, then after marking the bearing caps (so you can re-install them the same way later), remove them, spread the case (no more than .020"), and remove the diff. Mark the two halves with respect to each other, and the location of each pinion gear) then disassemble the two halves. Remove the side gears/clutch packs and keep them separated, and associated with the correct side of the case halves. Re-assemble with new clutches (soak all clutch material in LS-compatible gear oil), and re-install in the case halves. Align everything as it was marked before, and torque the case bolts 90-100ft.lbs. in a criss-cross pattern (like lug nuts). Spread the housing again, re-install the diff, put the caps back in proper location, torque cap bolts to 80 ft.lbs., put the axles back in (probbly need to lift the wheels to get the axle flange bolt holes to align), torque axle flange bolts to 95 ft.lbs. Diff cover bolts are 35 ft.lbs., by the way...

Good luck

Reply to
Tom Lawrence

Does it even have clutch plates? IIRC, the 2500 and 3500 have Torson based diffs (at least my 2500 HD does) which work differently. (Not that this makes a whole lot of difference, you're headed in the 'right' direction in replacing the whole set...)

Do keep us updated on your progress.

Reply to
PeterD

I'm not surewhich it has yet. Differential work is new to me and while I'm not afraid to tackle the project myself, I'm thinking of letting someone tackle it for me this time. Not sure yet....just considering it.

Reply to
Carolina Watercraft Works

Can you remove the cover without draining the oil?

beekeep

Reply to
beekeep

That'd be a neat trick, wouldn't it?

Of course if you had filled it with 800W gear oil, maybe you could?

Reply to
PeterD

I guess if I lifted the tail end up with my forklift completly vertical then I could remove it without draining it. That's a thought...hhhmmmm.

Reply to
Carolina Watercraft Works

If you do, please take pictures!

Reply to
PeterD

That happened with the switch to the AAM axles in '03. Dana axles ('02 and back, at least on the HD trucks) use a clutch-type LSD.

Reply to
Tom Lawrence

:^)

Reply to
Tom Lawrence

What do you think about the Detroit differentials? I do plow snow and pull people out of ditches when needed and I don't like losing drive when one wheel has no traction as has happened with me a couple of times in both snow and mud.

Reply to
Carolina Watercraft Works

You mean likea Detroit Locker? Had one in my '99... it worked well, but it takes a little getting used to on pavement - especially wet pavement. I haven't ran into a traction problem with my '03. The Torsen-type LSD's that Dodge uses in the AAM axles requires a little bit of resistance to engage. That means you need to two-foot it... a little brake and gas at the same time. If you've got a manual, give the e-brake a couple of clicks. Not enough to really bind, but enough to drag a bit.

Reply to
Tom Lawrence

They have a fully automatic LSD that performs like an open until needed: Detroit Truetrac

And they have the ELocker that I'm seriosly considering.

Reply to
Carolina Watercraft Works

Absolutely, and I'm surprised that few know this 'trick'. I do this with my 2500 as well, and I learned it from driving my Hummer H1, where this is a common trick (it has Torson's on both ends, and you can lock all four wheels like this.)

Reply to
PeterD

Slightly engaging te parking brake trick works on almost all differentials. I been using that trick when I get stuck in the mud for over 30 years now.

Reply to
Licker

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.