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did my screenshots of the 94 FSM and the Chilton manual load for you?
I just checked a '94 FSM 4B-29 and it mentions 9 specifically!!! 4B-29 in '94 FSM is specifications. I've never looked anywhere else for info. I believe I sent you your FSM!!
I just searched specifically 'rear axle fill' and damned if it doesn't mention 0B-8 the number you mentioned. The .pdf let me check that 'word term' specifically!! It ain't correct do 8 - 11 or 9!!!
** Until this post I've never checked the FSM for specifications for 'fill. drain etc' for rear diff. - not for the C4 or any others! As frequently as ZF fill/drain are discussed I understand someone 'looking'!
I just checked a '94 FSM 4B-29 and it mentions 9 specifically!!! 4B-29 in '94 FSM is specifications. I've never looked anywhere else for info. I believe I sent you your FSM!!
that's so weird, my 94 FSM also says 9 on page 4B 29, but in fluids and lubrication in section 0B it does say 30, which is where my SS came from. I will say this though: my fill plug turned quite easily up through, I'd guess, around 20/25 and was snug at 30. At 9 it would be very loose. Although I obviously wouldn't be able to tell if that would be because the last guy torqued to 30 or if that was factory intention.
you are correct in your first paragraph. 11ft lbs for 84-88, 84ft lbs for 89-94, and 11ft lbs for 96, according to the Chilton manual. I would definately torque your 89 to 30ft lbs. But if you do go with 11 check it after each drive for awhile.
I confirmed the 30ft lbs in my 94 FSM. 94 FSM Chilton 84-96
The reason why I'm asking is because my FSM for my 89 says to tighten the spark plugs to 25 ft/lbs, when in fact it's supposed to be 12 ft/lbs. So, I'm trying to understand why the torque spec would be different for different years when the rear carrier is supposed to essentially be the same for all the years? Unless there is something I don't know about.
The reason why I'm asking is because my FSM for my 89 says to tighten the spark plugs to 25 ft/lbs, when in fact it's supposed to be 12 ft/lbs. So, I'm trying to understand why the torque spec would be different for different years when the rear carrier is supposed to essentially be the same for all the years? Unless there is something I don't know about.
for the 94, at least, it saysit's a model 44 for manual and 36 for auto. They DO say 9ft lbs in section 4B but 30 in 0B. Is the 89 the same model? Why do you think it's supposed to be 12 if your manual states otherwise?
for the 94, at least, it saysit's a model 44 for manual and 36 for auto. They DO say 9ft lbs in section 4B but 30 in 0B. Is the 89 the same model? Why do you think it's supposed to be 12 if your manual states otherwise?
Regarding the spark plugs, the 89 FSM manual says 25 ft/lbs torque, but that is for the iron head L98's, the aluminum heads are supposed to be 12 ft/lbs. There are other places where the FSM has the incorrect torque listed.
So, I'm just trying to figure out what the deal is with the different torque values on the differential plug if they are all the same? I do remember a while back asking a shop to check the differential fluid level, and they told me the plug was torqued down really tight. So I guess I'll check around to see what torque value most people here are using.
Regarding the spark plugs, the 89 FSM manual says 25 ft/lbs torque, but that is for the iron head L98's, the aluminum heads are supposed to be 12 ft/lbs. There are other places where the FSM has the incorrect torque listed.
So, I'm just trying to figure out what the deal is with the different torque values on the differential plug if they are all the same? I do remember a while back asking a shop to check the differential fluid level, and they told me the plug was torqued down really tight. So I guess I'll check around to see what torque value most people here are using.
that's really interesting. Just curious, how would one go about verifying the FSM?
that's really interesting. Just curious, how would one go about verifying the FSM?
Yeah, I changed my spark plugs recently and I went by the FSM of 25 ft/lbs. As I changed them many years ago and forgot the FSM is wrong. But I was searching around for something and saw people mentioning the torque is 12 ft/lbs for aluminum heads. And I went out and loosened all of the spark plugs and torqued them to 12 ft/lbs. I got lucky as it looks like I didn't damage the threads. As that would be a real expensive mistake.
On my 89 FSM for the differential fill plug torque spec. On page 4B-27 it says "9 ft/lbs". But on page 0B-7 it says "30 ft/lbs". ???
I wonder if someone can check to see what Alldata says?
I went out and loosened the fill plug and put a torque wrench on it set to 9 ft/lbs, and it easily went past 9 ft/lbs. Unless someone reports back what Alldata says, I guess when I change my differential fluid. I'll torque it to say 15 ft/lbs and then spray the area with brake cleaner. And then keep an eye out on fluid leaks out the plug. I will say the plug was snug to whatever I torqued it to past 9 ft/lbs.
Just curious, why would alldata have have better info than the GM FSM? Their website says they get all their info from the manufacturers. I see they also say there are step by step instructions for the jobs, which the FSM doesn't really have. I mean, it does but they could be more detailed I suppose. FSM will say stuff like "seat the ball stud inside the clutch fork", and I was like.... ok what does that mean? So that makes me want to check out alldata.
So maybe someone could answer 1)why would they have have data that is more "correct" than the FSM and 2)are the "detailed step by step instructions" useful for more complicated jobs? Like how to adjust the shaft depth of the clutch, for example....
Just curious, why would alldata have have better info than the GM FSM? Their website says they get all their info from the manufacturers. I see they also say there are step by step instructions for the jobs, which the FSM doesn't really have. I mean, it does but they could be more detailed I suppose. FSM will say stuff like "seat the ball stud inside the clutch fork", and I was like.... ok what does that mean? So that makes me want to check out alldata.
So maybe someone could answer 1)why would they have have data that is more "correct" than the FSM and 2)are the "detailed step by step instructions" useful for more complicated jobs? Like how to adjust the shaft depth of the clutch, for example....
My understanding is as we all know the FSM sometimes contains errors that get's corrected later or sometimes GM decides to change something that was in an FSM at a later date, etc. My understanding is GM will put out bulletins or something detailing these changes, which of course won't appear in your FSM. So my understanding is Alldata will have all of these updates and changes and so will essentially have all the specs and instructions that are up to date vs what was printed 30 years ago that has no updates obviously.
The fact is the FSM shows two different torque specs in the same edition regarding the differential fill plug. I figured Alldata would have whatever the correct torque spec is supposed to be. Maybe someone who has a 1996 FSM can see if it lists two different torque specs for the differential fill plug? Maybe they got this mistake fixed in the FSM by 1996.
