Overhauling Disco front diff: Parts list or references

[The Dark Side of Will]

In this thread: http://forums.amceaglesden.com/index.php?topic=22813.0
I discuss a built Eagle driveline consisting of a 4.0, stock flywheel and clutch, NV3550, NP229, non-c-clip D44 3.54 rear and and D30 Disco 3.54 front from a 4 cylinder Eagle.

I finally popped the cover off the diff... looks like it had some water in it. I'm not sure how that happened, as it's been sealed the entire time I've had it.


Does anyone sell an overhaul kit for this diff? Is there an overhaul manual anywhere? I'd like to replace all the bearings and seals. The gears may be salvageable via electrolytic rust removal (e.g. http://realfierotech.com/phpBB/viewtopic.php?f=3&t=17528&p=142402 ).

Also, I understand that there are carrier differences between the D30 IFS and D30 axle related to pinion offset... is this correct? Where can I learn more?

EDIT: Interesting interchange info: http://forums.amceaglesden.com/index.php?topic=21608.msg207217#msg207217

[carnuck]

Pinion length changed between 80 and '82 somewhere I think. This is why you should drain and fill all diffs when you get a car. Especially 4x4. If water gets near the breather and the diff is hot, the sudden cooling draws it in through the breather.

The early non-vacuum diff has a 1.5" longer hanger on the passenger's side. The later non-vac ones are same as the vacuum ones.

As for kit, check http://ringpinion.com

If I weren't broke right now, I'd take my diff over there so I could get all those parts for mine.

I have the 2.72 front diff from my '82 on the for sale pile.

[vangremlin]

Is there an overhaul manual anywhere?

There is a pretty good write up in the TSM.  Have you looked there?  Good luck!

[The Dark Side of Will]

Pinion length changed between 80 and '82 somewhere I think. This is why you should drain and fill all diffs when you get a car. Especially 4x4. If water gets near the breather and the diff is hot, the sudden cooling draws it in through the breather.

The early non-vacuum diff has a 1.5" longer hanger on the passenger's side. The later non-vac ones are same as the vacuum ones.

As for kit, check http://ringpinion.com

If I weren't broke right now, I'd take my diff over there so I could get all those parts for mine.

I have the 2.72 front diff from my '82 on the for sale pile.

Thanks!

Is there an overhaul manual anywhere?

There is a pretty good write up in the TSM.  Have you looked there?  Good luck!

This?

http://amceaglesden.com/guide/index.php?title=1982_%26_1983_TSM

[Mernsy]

Here's a bit of info.

http://amceaglesden.com/guide/index.php?title=Rear_Axle/Differential_R%26R

[The Dark Side of Will]

Ok... so here's section 9 of the parts book:
http://amceaglesden.com/guide/index.php?title=Group_9_Axles_--_Propeller_Shafts

Here's the Disco parts diagram:


I made a .xls of the parts by group and part number, but I can't attach it to the post...

Code: [Select]

Group Part Number Nomenclature Amplification Description QTY
9.301-1 324 0159 4WD - With Part Time Axle (WPTA) 1981 FOUR 3.54 (13:46)
PO 9.303-1 Differential carrier bearing cap 2
PO 9.303-1 813 3625 HOUSING, Front Axle (Incl. Tube) 81 30-50 (WPTA)
813 4323 HOUSING, Front Axle (Incl. Tube) 82/83 30-50 (WPTA-* 9-2)
HOUSING, Front Axle (Incl. Tube) 83/ 30-50 (WPTA-* 9-3)

PO 9.368-1a 813 3610 SHAFT, Front Axle Drive 81/ (Inner-Right) 30-50 (WPTA) (Incl. Shaft, Cover, Seal, Bearing, Gear, Snap Ring, Screws) Right output flange 1
9.303-2 813 3608 ATTACHING PARTS, Axle Tube Cover 81/ 30-50 (WPTA) Right bearing plate bolt 4
9.368-2 813 3607 BEARING, Front Axle 81/ (Right Hand) 30-50 (WPTA) (Outer Bearing) Intermediate shaft bearing 1
813 4759 BEARING, Front Axle 81/ (Right Hand) 30-50 (WPTA) (Inner Needle Bearing) Intermediate shaft bearing
9.368-1 813 3606 SHAFT, Intermediate Front Axle Drive 81/ 30-50 (WPTA) (Incl. Needle Bearings and Snap Ring) Intermediate shaft 1

PO 9.368-1a 813 0752 SHAFT, Front Axle Drive 80/83 (Inner-Left) 30-50 (* 9-2) Left output flange
813 4585 SHAFT, Front Axle Drive 83/ (Inner-Left) 30-50 (WPTA * 9-3) Left output flange
9.368-2 813 2821 BEARING, Front Axle 80/83 (Left Hand) 30-50 (* 9-2) Left output flange bearing
813 4586 BEARING, Front Axle 83/ (Left Hand) 30-50 (WPTA * 9-3) Left output flange bearing
9.368-3 813 0762 SEAL, Front Axle Oil 80/83 (Left Hand) 30-50 (* 9-2) Left axle seal
813 4587 SEAL, Front Axle Oil 83/ (Left Hand) 30-50 (WPTA * 9-3) Left axle seal
9.368-6 813 0763 RING, Inner Axle Shaft Snap 80/ 30-50 C-clip 2

9.410-1 813 3609 COLLAR, Axle Shift 81/ 30-50 (WPTA) Disconnect shift collar 1
9.410-2 813 3617 FORK, Axle Shift 81/ 30-50 (WPTA) (Incl. Snap Ring, "O" Ring, Insert Kit) Disconnect shift fork 1
9.410-3 813 3618 SNAP RING, Shift Fork 81/ 30-50 (WPTA) Disconnect shift fork to actuator shaft snap ring 2
9.410-4 813 3708 INSERT KIT, Shift Fork (Incl. Inserts, Gasket, Screw, Lockwasher) 81/ 30-50 (WPTA) Shift fork friction inserts (?) 1
9.414-1 813 3616 COVER, Axle Shifter Housing 81/ 30-50 (WPTA) Disconnect cover
9.414-2 813 3624 ATTACHING PARTS, Shifter Cover WASHER 81/ 30-50 (WPTA) Disconnect cover washer
9.414-2 813 3623 ATTACHING PARTS, Shifter Cover BOLT 81/ 30-50 (WPTA) Disconnect cover bolt
9.414-3 813 3709 GASKET, Shifter Housing Cover 81/ 30-50 (WPTA) Disconnect cover gasket
9.415-1 813 3621 MOTOR, Axle Shifter Vacuum 81/ 30-50 (WPTA) (Incl. "O" Ring, 2 Snap Rings, Insert Kit) Disconnect actuator
9.415-2 813 3620 "O" RING, Motor to Housing 81/ 30-50 (WPTA) Disconnect actuator body o-ring
9.415-3 813 3619 SNAP RING, Vacuum Motor 81/ 30-50 (WPTA) Disconnect actuator body retaining snap ring
9.415-4 324 0501 SEAL, Vacuum Motor Drain 81/ 30-50 (WPTA) Drain fitting dust cap

9.341-1 812 6500 BEARING, Front Axle Differential Side 80/ 30-50 (Incl. 2 Cones and 2 Cups) Differential carrier bearing set 2
9.345-1 813 0760 SHIM SET, Front Axle Differential Side Gear Bearing 80/ 30-50 Differential carrier bearing shim set
9.318-1 G179890 SCREW, Bearing Cap 80/ 30-50 Differential carrier bearing cap bolt 4
PO 9.321-1 813 3720 CASE ASSEMBLY, Front Axle Differential 81 30-50 (WPTA) Differential carrier
813 3720 CASE ASSEMBLY, Front Axle Differential 82/83 30-50 (WPTA 20:47 Ratio) Differential carrier
813 4324 CASE ASSEMBLY, Front Axle Differential 82/83 30-50 (WPTA Except 20:47 Ratio) Differential carrier
9.336-2 636 360 PIN, Front Axle Differential Shaft 80/ Differential cross pin retaining bolt
9.336-1 812 0833 SHAFT, Differential Pinion Mate 80/ 30-50 Differential cross pin
9.333-1 812 0831 WASHER, Differential Pinion Gear Thrust 80/ 30-50 Spider gear thrust washer 2
9.327-1 813 3721 GEAR SET, Front Axle Differential Side And Pinion 81/ 30-50 (WPTA) Side & spider gear set 2
9.329-1 813 3724 WASHER, Differential Side Gear Thrust 81/ 30-50 (WPTA) Side gear thrust washer 2
PO 9.307-1 812 6498 COVER, Front Axle Housing (Incl. Plug) 80/30-50 Differential cover
9.307-2 991 546 ATTACHING PARTS, Cover to Housing SCREW 80/ 30-50 Differential cover bolt 10
9.305-1 G103869 PLUG, Axle Housing Fill 80/ 30-50 Fill plug
9.307-3 812 0360 GASKET, Front Axle Housing Cover 80/ 30-50 Differential cover gasket

9.350-2 649 454 ATTACHING PARTS, Ring Gear to Differential Case BOLT 80/ 30-50 Ring gear bolt 10
9.350-1 813 2831 GEAR SET, Front Axle (Incl. Pinion, Shims, Bearings, Seal, Slinger & Baffle) 80/ 30-50 3.54 (13:46) (Use 812 6518) Ring & Pinion
PO 9.355-3 812 6499 BEARING KIT, Front Axle Pinion Inner (Incl. 1 Cone and 1 Cup) Pinion rear bearing cup & cone
PO 9.355-4 812 4052 BEARING KIT, Front Axle Pinion Outer (Incl. 1 Cone and 1 Cup) 80/ 30-50 Pinion forward bearing cup & cone
9.357-1 813 0759 SHIM SET, Front Axle Differential and Pinion 80/ 30-50 Differential carrier & pinion bearing shims
9.364-4 934 937 BAFFLE, Pinion Bearing Oil 80/ 30-50 Pinion bearing oil baffle
9.364-3 916 372 SLINGER, Pinion Bearing Oil 80/ (Inner) 30-50 Pinion bearing oil slinger
636 566 SLINGER, Pinion Bearing Oil 80/ (Outer) 30-50 Pinion seal oil slinger
9.364-1 998 092 SEAL, Front Axle Pinion Bearing Oil 80/ 30-50 Pinion seal
9.404-1 813 3525 YOKE, Front Axle to Propeller Shaft 81/83 30-50 (Four) Input yoke
813 3241 YOKE, Front Axle to Propeller Shaft 80/ 30-50 (Six) Input yoke
9.350-5 636 570 WASHER, Pinion Nut 80/ 30-50 Washer (keyed?)
9.350-4 801 367 NUT, Pinion 80/ 30-50 Pinion nut
9.350-6 813 0758 SHIM SET, Front Axle Pinion 80/ 30-50 Pinion bearing shim set

[The Dark Side of Will]

Is there an overhaul manual anywhere?

There is a pretty good write up in the TSM.  Have you looked there?  Good luck!

This?

http://amceaglesden.com/guide/index.php?title=1982_%26_1983_TSM

Section 2F of the TSM is the one that covers the axles, and it is not available on the wiki.

[The Dark Side of Will]

Pinion length changed between 80 and '82 somewhere I think. This is why you should drain and fill all diffs when you get a car. Especially 4x4. If water gets near the breather and the diff is hot, the sudden cooling draws it in through the breather.

The early non-vacuum diff has a 1.5" longer hanger on the passenger's side. The later non-vac ones are same as the vacuum ones.

As for kit, check http://ringpinion.com

If I weren't broke right now, I'd take my diff over there so I could get all those parts for mine.

I have the 2.72 front diff from my '82 on the for sale pile.

How do I tell which pinion length I have?

There doesn't seem to be much in the way of overhaul info or parts for the disconnect mechanism (IE, all the little bearings and junk associated with it).

Next step is to knock the diff apart and see what actually needs replacement.

[carnuck]

With the axle out or at least hanging down enough you can use large measuring calipers to measure from the center divot of the front to the middle of the gear face.

[The Dark Side of Will]

With the axle out or at least hanging down enough you can use large measuring calipers to measure from the center divot of the front to the middle of the gear face.

Not visualizing what you're talking about.
Do you mean "pinion offset" instead of "pinion length"?

[The Dark Side of Will]

If I filter these tables for 3.54 Disco:

I get this table

Code: [Select]

Disco 3.54

Year BOM R&P Case Assy Case Left OP
1981 610134-5 700128-6 706819X 700130 620516
82-82.5 610153-5 706819X 700130 620516
83-84 610174-5 706830X 706831X 620842

I don't know what year car my diff came from.
Is the part number anywhere on the carrier ("case" per AMC) to let me figure out which one I have?
All the 3.54 apps use the same R&P, though. Since I'm starting with a 3.54 diff and (probably) replacing 3.54 gears, I shouldn't have any problems. It's only when swapping out for 2.35's that people have problems, AIUI.

[carnuck]

So maybe it's just when swapping to different year cases that it doesn't work? As for the measurement.

http://www.greenfries.info/images/Rear_gear/DSC04741.JPG

http://www.macysgarage.com/myweb6/images/DCP_3242s.JPG

http://www.macysgarage.com/myweb6/diff-overhaul.htm

(even though it's Brit bits, the theory is the same)

[The Dark Side of Will]

My dad and I did a bunch of disassembly on the diff unit today...

The pinion and/or diff bearings are so cruddy that I had to use a pretty big lever to turn the unit to the point that I could get the C-clips out of the diff.

Once the left C-clip is out, the left output flange pulls right out, leaving its seal and bearing in the case. We haven't gotten those out yet.

The disco cover unbolts and the disco shift fork comes out with it.

The seal retaining plate under the right output flange comes out with 4 socket cap screws. There's an access hole in the flange that allows a tool onto the fasteners. We had to put a couple of bolts into the flange and use a slider hammer to get it out, but it comes out with the retaining plate, seal, bearing and disconnect "gear". The gear is a light press onto the splines and ALSO retained with a snap ring. The cone is a light press onto the shaft.

Once the right output flange is out and the right C-clip is removed, the intermediate shaft slides right out. There's a small roller bearing just inboard of the disco box that supports the right end of the intermediate shaft. We have not removed this yet. The TSM calls out J26225 to remove this bearing. This tool is also used on T5 transmissions and is readily available on ebay.

We pulled the diff carrier bearing caps and found the cup numbers shown below, but we don't have the case spreader tool required to get the carrier out, so we stopped there. The tool is a 24385-01, which has many applications and is available on ebay from $120ish.

We may be able to use a slide hammer to get the left bearing & seal out, but will most likely be able to knock them out more easily with a punch once the carrier is removed.

Here are the part numbers we liberated today:
LM501314   Cup - Diff carrier bearings

U261L      Cup - Right flange bearing
U298      Cone - Right flange bearing
35938-1      Seal - Right flange

543290      Seal - Left Flange

J26225      Intermediate shaft roller bearing removal tool
J24385-01   Case spreader set

[eaglebeek]

We pulled the diff carrier bearing caps and found the cup numbers shown below, but we don't have the case spreader tool required to get the carrier out, so we stopped there. The tool is a 24385-01, which has many applications and is available on ebay from $120ish.

I rented a carrier spreader last time I needed one. Perhaps there's a shop in your locale where you can do likewise.

[The Dark Side of Will]

My dad knows a couple of guys around... we'll talk to them this week.

I can ask at CarQuest or similar if they have one... but I doubt it.