Great rear rotor video

[92landyacht]

Found these videos online and thought I'd share.

I'm planning to do a complete rear brake rebuild this spring and getting things ready for the job. Found this video and it answered many questions I had on servicing the rear brakes on a P32 chassis.

https://www.youtube.com/watch?v=0Mvth3L44aU&t=2s

https://www.youtube.com/watch?v=M4cETjMOtL8

The goal is to replace the calipers, rotors, pads, rear wheel seal, lug bolts and center rubber brake line. The left and right-side rubber lines were replaced a few years back.

Currently have the rotors, calipers, brake line and pads at the house. Still need to pick up the rear seal but need to identify exactly which rear end I have in order to order it. Seems like there were several different seals used depending on which rear diff I have. I could measure the seal but then I would have to remove the rotor first and wait for the parts to arrive or hope that a local parts store has it in stock.

If anyone can add any comments to what the video is saying or any other things I should be looking for, please feel free to share. I only want to do this job once.

[Kvsterling]

I don’t think you are missing much here. Believe the rear axle is Dana 70 HD. The seal may be a remove and measure to replace. Can’t remember which year they went to Dana 80.

Also, may want the socket used to remove those lock nuts. Not that removal is so bad, but there is a specific process for torque while turning the hub to load the bearings. I wouldn’t want to guess

[92landyacht]

Originally Posted by Kvsterling

I don’t think you are missing much here. Believe the rear axle is Dana 70 HD. The seal may be a remove and measure to replace. Can’t remember which year they went to Dana 80.

Also, may want the socket used to remove those lock nuts. Not that removal is so bad, but there is a specific process for torque while turning the hub to load the bearings. I wouldn’t want to guess

I'll look more into which rear end I have. Unfortunately, a few years ago, I had a truck repair shop fix a faulty speedometer issue. Turned out to be a faulty drive module, but they needed to count the ring and pinion gears to verify which one to replace it with. In the process they removed the metal tag on the rear cover bolt and never replaced it. Makes it harder to identify which rear end I have. I guess I'll keep looking.

I already have the socket used to remove and replace that lock nut. Picked that up at the same time I picked up the rotors, calipers and pads.

[cmadmaxman]

GM went to the Dana 80 in 91 when they put the 4L80E transmission.

Brakes are just about the same as the Dana 70HD on the early 80's. I'm thinking the duel piston calipers did not show up until the Workhorse chassis!?

I did a job on a 2001 3500HD chevy truck with the Dana 80 and bigger rotors, but still had the single piston.

[92landyacht]

Originally Posted by cmadmaxman

GM went to the Dana 80 in 91 when they put the 4L80E transmission.

Brakes are just about the same as the Dana 70HD on the early 80's. I'm thinking the duel piston calipers did not show up until the Workhorse chassis!?

I did a job on a 2001 3500HD chevy truck with the Dana 80 and bigger rotors, but still had the single piston.

It is a 1992 model, and it does have the 4L80E transmission.

I think that I've been able to confirm that it is indeed a Dana 80. Looking over the differential today, I found the number 80 cast into the housing. The size of the axle tubes appears to be larger in diameter than a Dana 70. Probably around 4 inches in diameter. Didn't have a caliper to measure it exactly. Right now, I'll assume it is a Dana 80 and pick up parts as needed.

[92landyacht]

Can someone confirm that a Dana 80 is a Spicer 80? I have two seals from National Oil Seals PN 6358 and they're for a Spicer 80 according to Rock Auto.

[cmadmaxman]

Here is the seal I used for the rear hub: National Seal 40235.

On bearings and seals, if in doubt, I like to have them in hand and order from a great parts store here that sells Timken bearings and seals as well as National.

Return to Rock auto can sometimes get risky if you have ordered wrong parts! Have a couple of times, with some seals and bearings, and was just better to not return em! Return shipping wiped out the savings!

[cmadmaxman]

Sorry about the upside down phots. If you rotate them with an edit, this site will always flip them back to the original! O well, cant have everything!

[bkahler]

Originally Posted by cmadmaxman

Sorry about the upside down phots. If you rotate them with an edit, this site will always flip them back to the original! O well, cant have everything!

Sometimes when this happens I will take the picture and reduce the size by 1 pixel and then rotate it. That seems to work for me.

[cmadmaxman]

Thanks Brad, I will give it a try.

[92landyacht]

Originally Posted by cmadmaxman

Here is the seal I used for the rear hub: National Seal 40235.

On bearings and seals, if in doubt, I like to have them in hand and order from a great parts store here that sel40235ls Timken bearings and seals as well as National.

Return to Rock auto can sometimes get risky if you have ordered wrong parts! Have a couple of times, with some seals and bearings, and was just better to not return em! Return shipping wiped out the savings!

Attachment 412034

Attachment 412035

Attachment 412036

Not sure we have the same rear end but everything I've found seems to indicate that the National part for the Spicer 80 is 6358. Can't find the 40235 part number anywhere. Just need confirmation that Dana and Spicer are the same for a chevy.

[cmadmaxman]

Julius, I would make sure that you have seal in had, just incase!

We should have the same rear if it looks like the photo of my hub. There was not much changes of the 80 in the early years used on GM.

Eaton I believe is just a supplier of components that would/could be used in the Dana 80 and other driveline products.

When I did the Dana 70HD on the 310, the brakes and hubs were, as far as I can tell, the same. In fact I ordered the same brake parts for both units!

The retainer nuts just a little different, that the 70HD did not have the slots go clear across the nut face, so the nut driver would not work until I slotted the nuts completely!

[92landyacht]

Originally Posted by cmadmaxman

Julius, I would make sure that you have seal in had, just incase!

We should have the same rear if it looks like the photo of my hub. There was not much changes of the 80 in the early years used on GM.

Eaton I believe is just a supplier of components that would/could be used in the Dana 80 and other driveline products.

When I did the Dana 70HD on the 310, the brakes and hubs were, as far as I can tell, the same. In fact I ordered the same brake parts for both units!

The retainer nuts just a little different, that the 70HD did not have the slots go clear across the nut face, so the nut driver would not work until I slotted the nuts completely!

I still can't find a seal with that specific part number. Do you have a source?

[cmadmaxman]

I will check with my supplier tomorrow morning and get back with you.

Thought I had a photo of the box, but of course not!

[Boom Sounds]

Axle intell.

[Boom Sounds]

Select year, then select GM Trucks, then Motorhome. Voila

https://www.gmheritagecenter.com/gm-...tion-kits.html

[92landyacht]

Originally Posted by cmadmaxman

I will check with my supplier tomorrow morning and get back with you.

Thought I had a photo of the box, but of course not!

I think I know why I couldn't find the part number you posted. It's not 40235, it's 40285. That part does cross over to a Spicer/Dana 80 1992 model. I'll pick one of those up as well.

Edit:
For what it's worth, National P/N 6358 crosses over as an alternate part for 40285. So, I guess, we were both right. Oddly, the 40285 part is not listed for use in a 1992 P30. Most parts stores show its usage for a 98+ GM P30 while the 6358 is used before then. Not sure why since both have virtually identical inner and outer dimensions.

[92landyacht]

Originally Posted by Boom Sounds

Axle intell.

This is exactly what I was looking for. It does show that the Spiicer/Dana part number is 40285. It also states that there is no gasket seal between the axle cover. It states to use silicone sealer.

[cmadmaxman]

Good to hear Julius, will save the information. Minor changes in seal technology changes, and so, will change the number even if physical the same sizes!



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[92landyacht]

Originally Posted by cmadmaxman

Good to hear Julius, will save the information. Minor changes in seal technology changes, and so, will the number even if physical the same sizes!



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That may very well be the difference. Most locations show the seal material on the 40285 as being simply Rubber while the National 6358 show as Nitrile Rubber (NBR). Since I already have the 6358 seals in hand I'll probably go with them. I don't see any reason to pick up the 40285 seals right now.