unit bearings/axle seal

i am planning on upgrading my 87 dana 30 disco 260 u-joints to non-disco 297 u-joints.

Question #1 do i use the same unit bearing that are in my axle or do i need to use a different outer knuckle?

Question #2 what seals do i use?

Question #3 I have read that i need to remove the gears w/ carrier and press in new seals or can i just remove the vaccum disconnect pull the seal and press in new seals through that and NOT remove the carrier?

lgorman00 said:

i am planning on upgrading my 87 dana 30 disco 260 u-joints to non-disco 297 u-joints.

Question #1 do i use the same unit bearing that are in my axle or do i need to use a different outer knuckle?

Question #2 what seals do i use?

Question #3 I have read that i need to remove the gears w/ carrier and press in new seals or can i just remove the vaccum disconnect pull the seal and press in new seals through that and NOT remove the carrier?

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Ill Take a stab since I'm getting ready to do the same sorta and if I'm wrong I would like to know it now..

1: You can use the same Uni and just swap the shafts but you may want to change out the knuckle, uni and brakes since I "think" they are stronger on 91+ d30s and should swap right over

2: Use the seals for a Non-disco D30

3: Yes to press in the seals you need to remove the carrior (not a big deal really) and you don't want to run the disco seal because the one piece inner on the passanger side has no seal surface were the disco seal is so it would just leak the disco d30 can have the seals put in both sides of the pumkin just like a non-disco (right?)

Zipdrive007 said:

1: You can use the same Uni and just swap the shafts but you may want to change out the knuckle, uni and brakes since I "think" they are stronger on 91+ d30s and should swap right over

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The 91+ knuckles are not stronger, nor are the brakes. There are offset differences. There is no reason to swap hubs or knuckles, so don't.

2: Use the seals for a Non-disco D30

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This works for the driver's side, but the passenger side isn't machined to accept a seal at the point where the axle tube enters the diff housing. I believe our illustrious past president, Woody, went into his and used a Dremel to clean out the opening enough to accept a seal. I suggest you consult him, and please post what he said on this thread so others can see it.

3: Yes to press in the seals you need to remove the carrior (not a big deal really) and you don't want to run the disco seal because the one piece inner on the passanger side has no seal surface were the disco seal is so it would just leak the disco d30 can have the seals put in both sides of the pumkin just like a non-disco (right?)

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When converting to non-disco shafts you should remove the seal at the disco motor.

why wouldn't you just use a driver's side seal on the passenger side at the disco motor? Is the axle tube a different diameter there?

WobblesXJ said:

why wouldn't you just use a driver's side seal on the passenger side at the disco motor? Is the axle tube a different diameter there?

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yes it is the outside tube past the disco is a sleeve inside the tube...plus the shaft is unfinished at the seal location if it is a one piece inner...would be kinda like sandpaper on the seal and I believe the shaft diameter is small at that piont verses a 2 piece disco. What gets me is how many people I have heard say yah just put a cover plate on an do your seals and the shaft work great...so far it sounds half#@$$ed if to use the passanger side seal from a non-disco you have to "dremel" it out and i have NEVER heard that part talked about.

so do i just remove the seal at the disco?
And put a seal where the axle shaft meets the carrier.
Plus, does anyone know what kind of seal to use?

lgorman00 said:

so do i just remove the seal at the disco?
And put a seal where the axle shaft meets the carrier.
Plus, does anyone know what kind of seal to use?

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The only thing I know for sure now is that if you ugraded to 95 YJ shafts you would have the 297 joints and still have the 2 piece pass side disco.

Zipdrive007 said:

yes it is the outside tube past the disco is a sleeve inside the tube...plus the shaft is unfinished at the seal location if it is a one piece inner...would be kinda like sandpaper on the seal and I believe the shaft diameter is small at that piont verses a 2 piece disco. What gets me is how many people I have heard say yah just put a cover plate on an do your seals and the shaft work great...so far it sounds half#@$$ed if to use the passanger side seal from a non-disco you have to "dremel" it out and i have NEVER heard that part talked about.

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The RS tube inner diameter is smaller on a disco axle than on the non-disco... by about 2-3mm. I ground out my tube to get clearance for the factory seal (since that was what I had) but IIRC Randy's now offers a seal that fits the disco tube without grinding.

IIRC someone posted the part number for that seal a week or two ago in another thread... a search ought to point it up.

woody said:

The RS tube inner diameter is smaller on a disco axle than on the non-disco... by about 2-3mm. I ground out my tube to get clearance for the factory seal (since that was what I had) but IIRC Randy's now offers a seal that fits the disco tube without grinding.

IIRC someone posted the part number for that seal a week or two ago in another thread... a search ought to point it up.

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Thanks for the steer Woody

ChuckD said:

Well I guess it's my lucky day.

Thanks to RawBrown, Google, and Michigan Jeepers Forum!

Here are some part numbers

CR 11800 and Warn 37897

Here are the dimensions:
2.062 OD
1.25-1.2 ID
.25 H

PartsAmerica has both listed for about 7-10 ea. The problem is that they want $5.00 for shipping and it will take at least 5-7 days for ground.


Chuck D
Member#502

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ChuckD said:

Update on the seal part number!

The CR 11800 is a bit too big, you could probably make it work but you will have to grind out the inner tube a little.

This seal should just tap right it, 11771/40576S CR SEAL

Also, the 91' disco axles may be machined for the standard carrier seal. We found this out talking to a 4WD shop, who at first sold me the wrong seal. Then I found out that its a 60's CJ5 has a front axle seal.

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Thanks to Chuck for the part numbers