Mojave

After 150K miles and countless auto-x and track miles, my limited slip is losing the limited and gaining more slip. Has anyone repacked their own diff? I know on a Mustang Trak-Lok it is a fairly straight forward procedure that does not require the removal of the carrier from the housing. Is this also true for a D44?

The factory service manual isn't particularly clear in this area. Mustangs use an S-spring to load the spider gears, but from looking at the manual it appears the D44 uses something else.

RichS

You need to tear it all out. The clutch is springloaded onder each side. You need to remove the crosspin to get the guts out. They make a special tool for repacking them and getting the spiders and pin back in. It's not too bad to do but a little of a pain in the azz.
You can get a clutch pack for about $50 from any differential parts place, The spiders are hard to find and a new Posi is around $300.

Mojave

Is the special tool required or recommended?

WVZR-1

If you could put your hands on the correct tools it would be "good"! Are the tools "required"? No!

You'll need to be a little "creative" but it's certainly "doable"!

If you've never replaced the rear bearings and seals it's certainly "time"!

You could carry the the rear to the shop and have them do the bearings, seals and required "set-up"! A quality build now could save you considerable effort and expense later!!

Mojave

While replacing bearings and seals is not a bad idea, it's not leaking or whining, which makes me hesitant to jack with it. I definitely don't have the tools or experience to setup a ring and pinon, but I could get it out of the housing and repack the clutch plates.

WVZR-1

I've always done bearings, seals, clutches etc as a routine service! Maintenance!!

If you were "creative" you could do the clutch pack I believe with out removing the carrier from the housing. If you're not going to do bearings there's "no reason" to remove the carrier! You would need to replace the "short-axle" seals but it would be "silly" not to do these and the bearings for at least the "short-axle" while you were there!

You could likely re-use the the selective snap-rings that retain the short-axles for the pre-load on the clutch pack!

I have never done a D36 or D44 this way but I believe it's quite doable!!
Very "doable"!!

If you don't want to do bearings and get the rear "set-up" you need to leave the carrier in the housing!! "NEED TO"!!!!

Mojave

Do you know what controls the play on the stub axles? I've got play and it's causing play at the rear wheels which is quite annoying. I think a washer or washers go under the snap ring. Doing it right would be to replace everything, but all those details add up...

WVZR-1

I'd say it needs "re-freshed"!! You could likely find that the "pinion shaft" has worn the case/carrier in which case you can forget the "clutch-pack" only.

My only and maybe best suggestion might be: "remove the differential" and get "professional help"!! You're attempting to "short-cut" a known "preventive maintenance" procedure and it's simply asking for "more trouble"!

Here is a possible "senario" if you leave it alone and do nothing! If the pinion shaft/case fit is bad you'll "spit a pinion gear or both through the case "floor"!
You'll know then what it needs!

You need to buy a bearing/seal (6 bearings, 3 seals) kit, a clutch pack to be prepared. Remove the rear and inspect "everything". There's "no short-cut"!!!

Mojave

You're right, but it makes he sad to think of spending $600+ parts and labor on it.

WVZR-1

I don't see $600 if you do the R & R yourself! If you don't need a case or any "hard-parts" I'd think $400 should do it right. Maybe less! If you need a case/carrier or short-axles more for sure!

I've got "most" D44 parts!

Mojave

I can get it out no problem. I really see no reason I'd need a case, carrier, or any other hard parts. Other than a not so limited diff and play in the stubs, I don't have any issues.

RichS

The stub axles are held in with a large snapring. They are various thicknesses to set the endplay of them. They have nothing to do with cluchpack preload/tightness. You need a stout pair of snapring pliers to get them out. I broke alot of cheap pairs getting them out.

I doubt you could get the crosspin out easily with the carrier still installed. You need to punch out a roll pin that holds the crosspin in. It would hit the case or bearingcaps.

There are spring washers that are installed under the cluchpack. These are what controll the tightness of the pack. You can add more shims under these to tighten up the pack. If you go too tight it will be inpossible to get the spiders and crosspin back in. The proper tool compresses the packs so you can get the spiders/pin back in. I've made pieces out of bolts and washers to do this but need to but the proper tool to make it easier.

One way to test if the clutch pack is worn is jack up oneside of the rear and rotate the tire. If it rotates easily to pack is worn. It should be very hard to turn the one wheel.

I've broken and repaired a ton of these, and they aren't too bad to repair but parts are getting rare!

Mojave

I did the 1 wheel turn test and it is not very hard to spin, which is not surprising considering the 1 wheel peel I've experienced. I guess I'm going to go ahead and pull the diff and get the entire thing rebuilt, including a clutch repack.

BrianCunningham

MTVette just redid his, he said there's new internals for them now.

PM him for details.

jmartynuska

I just had my car up for some work so I thought I'd try the test...

Yup, turned easily.

Looks like a rebuild in my future.

Chad, are you going to do the job yourself or farm it out? if you have any tips along the way I'd appreciate any advice.

Good luck!

Jeff

(Jeff97FST/A on FRRAX)

jhammons01

Yes, the "Rings from hell" are specifically sized and color coded.

First you'll need to buy the GM special tool to remove them from the stub axles or you can buy a snap ring pliers and modify them to specifically fit the holes in the "Rings from Hell"


I used a dremmel and a propane torch to first shape and then bend (respectively) to fit those rings.


You'll have to set up a dial gauge to check the end play....it should be no more than .004".......if there is more you'll have to buy other rings. The rumor (not verified by me but coming from PeteK....reliable source) is that the rings are ~$80 for a set. So you do not want to break the ones on the stub shafts.

There is no way to get the carrier out without first taking the "Rings from Hell" off.

Be careful of folks telling you that this is a job you can do in your driveway. Just the three seals and bearings to "freshen up" a rear end is over$100 in cost......this does not include install NOR DOES IT include any cost of the LSD unit.

All the invoices I saw at my Diff specialist had well over $600 in parts and the R&R for the LSD unit was well into the $1000 dollar range....benched....meaning you pull the Diff and take it to the guy.

Mojave

Jeff, I'm going to pull it out and have someone else do it. I only want to do this once and diff work is not my specialty. Not to mention the clips from hell pictured above.

Thanks for the info. Its good to see pics and hear from someone who has actually tried this. I don't feel like fighting with the clips from hell, nor worry about getting the rest of the setup right. I need to measure the end play on my stub shafts, but I'm sure it's more than .004", as my rear wheels move due to play in the stubs.

On a related note, has anyone used poly batwing bushings? I'm not sure what condition my bushings are in, but I suspect it's not good.

jhammons01

^^ I wouldn't...there are just so many things I saw in that shop that the average guy wouldn't have knowledge of.....Also...getting info from here just two weeks ago was like pulling teeth....Lot's of Theory but when the rubber met the road I found out that I was on my own. Almost all the info I gave to you was told to me directly from my Diff Specialist that earned top 25 tech in the Nation from GM. He also taught the course on Differentials.

Let me know if you are interested in shipping the unit to the west coast for servicing....I wouldn't think you would, but I don't have any references from Houston or Austin for Differentials

Mojave

He sounds like he really knows his stuff. I'm getting a local referral from a fellow auto-xer.

mtwoolford

I installed the poly bat wing bushings. Once you get far enough into it to drop the bat wing, it would be counterproductive not to do it. Have a good 1/2 drive breaker bar and appropriate sized six sided socket to break loose the original nut and mounting bolt. Dropping the bat wing was a one man job; it really helps to have a second pair of hands when it came time to guide the bat wing back into place.

Replacing the bushings was easy. And I am very satisfied with the results.

A word of caution; once you get everything apart, and I mean basically the whole rear suspension has to come apart to even get the rear differential out, you'll find yourself wanting to replace everything, u joints, all the other bushings, possibly the shocks, etc. Plan ahead and budget accordingly!

Good luck, let us know how your project turns out; and if you care to, the cost.