i have a diff that is growling at me. im going to get the bearings and crush sleeve replaced. Does anyone know if super tech 80w90 is any different then most others. I really am not interested in running synthetic. I was actually thinking about running one of the 90w140 oils just because it is so old. The truck will probably not get fwd used but maybe 2 times a year. Also i will probably be changing the fluid every 30 to 50k miles. I have not seen any VOAs on diff fluid. I have used ST many times before, especially for flushes and it seems to do fine. The suburban is used mostly as a minivan. We use it to carry the kids around and stuff so there is little to no heavy duty use.
99 suburban, diff rebuild, 180k miles, fluid?
- Thread starter jstutz
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I would use the 85w140 and just change if often using a magnetic plug. I would not waste the money on the bearings and crush sleeve and save for the rebuild. It may very well be the ring and pinion going away. Is their excessive metalic material in the lube in the past when you drained it?
i do have a magnetic drain plug and there was some metal shavings on there. Net excessive but it was definatly there. I just dont think it is the gears because it didnt start making noise until i replaced the pinion seal. Im pretty sure that i screwed up the crush sleeve or the bearings. there is a shop nearby that said they would look at it for me. im going to take the diff down tonight and let him look at it friday. If i decide to do a rebuild, is there a site that you all have used to order an entire rebuild kit that had gears, bearings, seals ect. i dont want to get into spending 1k on this diff. if it comes near that i may just make it 2wd.
Is this the front differential on your Suburban? If so, you don't need anything heavier that a 80W-90 in there.
Use the ST synthetic 85w140 or Valvoline Durablend 80w90 which is about $6.99 at autozone.
Originally Posted By: jstutz
i do have a magnetic drain plug and there was some metal shavings on there. Net excessive but it was definatly there. I just dont think it is the gears because it didnt start making noise until i replaced the pinion seal. Im pretty sure that i screwed up the crush sleeve or the bearings. there is a shop nearby that said they would look at it for me. im going to take the diff down tonight and let him look at it friday. If i decide to do a rebuild, is there a site that you all have used to order an entire rebuild kit that had gears, bearings, seals ect. i dont want to get into spending 1k on this diff. if it comes near that i may just make it 2wd.
If this is the case a front carrier bearing might just do the trick. Let the shop put the bearing and seal in this time. You may have over-torqured it?
i do have a magnetic drain plug and there was some metal shavings on there. Net excessive but it was definatly there. I just dont think it is the gears because it didnt start making noise until i replaced the pinion seal. Im pretty sure that i screwed up the crush sleeve or the bearings. there is a shop nearby that said they would look at it for me. im going to take the diff down tonight and let him look at it friday. If i decide to do a rebuild, is there a site that you all have used to order an entire rebuild kit that had gears, bearings, seals ect. i dont want to get into spending 1k on this diff. if it comes near that i may just make it 2wd.
If this is the case a front carrier bearing might just do the trick. Let the shop put the bearing and seal in this time. You may have over-torqured it?
Originally Posted By: Johnny
Is this the front differential on your Suburban? If so, you don't need anything heavier that a 80W-90 in there.
and Johhny's right, a 90w will work fine. I was trying to extend a bearing failure or ring and pinion failure with the additional weight gear lube.
Johhny sorry to see they tossed your avitar....it will take a while to notice you without it.....bar reading your posts and seeing your retirement info.
Is this the front differential on your Suburban? If so, you don't need anything heavier that a 80W-90 in there.
and Johhny's right, a 90w will work fine. I was trying to extend a bearing failure or ring and pinion failure with the additional weight gear lube.
Johhny sorry to see they tossed your avitar....it will take a while to notice you without it.....bar reading your posts and seeing your retirement info.
Carrier bearings on GM front axles are famous for taking a dump. Please if you can post the manufacturers name on the bearings that come out.
just talked to the guy that is working on my diff. It is indeed the carrier bearing. He said it likely did not have anything to do with what i did. We are trying to locate a rebuild kit. Any good online recomendations? I will be meeting with him in the morning and get the information for the bearings you wanted. The guys working on it for me is a pretty nice guy and is only charging me 1500 dollars.
Ask him if the carrier was forged or powdered metal. Those boneheads at AAM decided that PM was cheaper and forgot it flexes more than a forged piece which starts screwing the bearing alignment. More stupid cost cutting from GM & AAM.
Well cast is many times PM and will flex. I would change out the diff lube in 5000 miles. If it comes out real black beware it may dump again.
Kestas
Staff member
I am involved with one of the carrier manufacturers (that shall remain unnamed) and their use of our bearing in their carrier designs. Though we provide quality bearings that are as good as anybody else's in the market, I am asked to evaluate the bearings that fail their evaluation tests. Nearly always I find that the bearings are overloaded and insufficiently lubricated by design. So whoever made the bearings for your carrier may not be at fault, and it may be the poor design of the carrier.
It's an all-too-common theme I see with designs that use our bearings... the manufacturer cuts all kinds of robustness out of their product and expects too much out of the bearing. On paper, the numbers look good. But testing shows the shortcomings of their design. Sometimes they just don't get it, and it frustrates us to no end.
That's not to say that this is the case for your suburban. Only a good analysis of the bearing and differential can reveal the true cause of failure. Sometimes failure is from what we call and "inclusion spall"... meaning there was an inclusion in the steel that was in the "sweet spot" of the bearing. There's nothing that can be done about that type of failure. No bearing-quality steel is perfectly clean. It's happenstance, and this failure can happen to the best of bearings. When you manufacture a large volume of bearings, some will fail from inclusion spalling. It's unavoidable.
It's an all-too-common theme I see with designs that use our bearings... the manufacturer cuts all kinds of robustness out of their product and expects too much out of the bearing. On paper, the numbers look good. But testing shows the shortcomings of their design. Sometimes they just don't get it, and it frustrates us to no end.
That's not to say that this is the case for your suburban. Only a good analysis of the bearing and differential can reveal the true cause of failure. Sometimes failure is from what we call and "inclusion spall"... meaning there was an inclusion in the steel that was in the "sweet spot" of the bearing. There's nothing that can be done about that type of failure. No bearing-quality steel is perfectly clean. It's happenstance, and this failure can happen to the best of bearings. When you manufacture a large volume of bearings, some will fail from inclusion spalling. It's unavoidable.
Originally Posted By: Kestas
Nearly always I find that the bearings are overloaded and insufficiently lubricated by design. So whoever made the bearings for your carrier may not be at fault, and it may be the poor design of the carrier.
It's an all-too-common theme I see with designs that use our bearings... the manufacturer cuts all kinds of robustness out of their product and expects too much out of the bearing.
You are 100% right...now I'm not naming any suppliers either but lets just call the supplier Samerican Axle..
so the guys at SAM want to save a few bucks and cheap out the carriers. What happens...they lose the rigidity of the part and what fails? Not the carrier...the bearings...the same bearings that were fine with a forged carrier. DOH....hello GM? Notice how lots of SAM differentials are only lasting 40,000 miles? Go back and look at what was changed instead of burning the bearing guy. Just visit the GMC Yukon Denali forum and you will see many unhappy customers wondering why their diffs went south within 40-50k
Nearly always I find that the bearings are overloaded and insufficiently lubricated by design. So whoever made the bearings for your carrier may not be at fault, and it may be the poor design of the carrier.
It's an all-too-common theme I see with designs that use our bearings... the manufacturer cuts all kinds of robustness out of their product and expects too much out of the bearing.
You are 100% right...now I'm not naming any suppliers either but lets just call the supplier Samerican Axle..
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Wow, it seems as though this is not my problem right. unless it went bad in .25 miles. I found a post somewhere that i would like to run past you guys that actually know about this stuff.
post
Recently the truck will grind when taking off from a stop. This only happens in 2-hi and when in 4-hi no noise is heard. Sounds like the grinding is from the transfer case area. The truck has the floor shifter. Does anybody have knowledge of possible electric failure or likely a mechanical defect?
Answer
Hello,
There is a lockring the breaks right in the little tailhousing on the back. This lockring holds the main shaft in place, when it breaks the shaft will move with motion. All the gears and synchros are on the main shaft and lets the gear it the slider ring and grind. They make a fix for it so it will never do it again. If you are interested in checking or fixing it, let me know and I can tell you how step by step.
post
Recently the truck will grind when taking off from a stop. This only happens in 2-hi and when in 4-hi no noise is heard. Sounds like the grinding is from the transfer case area. The truck has the floor shifter. Does anybody have knowledge of possible electric failure or likely a mechanical defect?
Answer
Hello,
There is a lockring the breaks right in the little tailhousing on the back. This lockring holds the main shaft in place, when it breaks the shaft will move with motion. All the gears and synchros are on the main shaft and lets the gear it the slider ring and grind. They make a fix for it so it will never do it again. If you are interested in checking or fixing it, let me know and I can tell you how step by step.
Okay, well i just put the truck up on stands and put it in drive and could hear the grinding. i climbed underneath and sure enough the sound is coming from the transfer case. Sounds like around where the front shaft goes into it. So im thinking/hoping that it could be just a bad bearing there? what are your thoughts.
Sounds possible. I would drive it down to the guy that put the bearing in your differential and let him look at it.
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