The Stupid Axle Questions Thread

Kiko_Jones said:

My mechanic is telling me I need to consider rebuilding the Diff on my 1996 GMC 1500 W/T. The options are rebuild or replace with good used.
If I were to go with the replacement, what years are compatible? Cause I can swap a rear end and save the labor.

Click to expand...

Kiko_Jones said:

Thank you for the quick reply. It's a 2wd with a 10 bolt with a 4.3 V6
Can you talk to me more about the 3.73 upgrade? I'm planning on a 4/6 drop. I use it to drive to the Home Depot for Mulch and other non-sense.

Click to expand...

First of all, is your rear end making noise? If not then why fix what isnt broken. That being said, I just rebuilt my rear end in my 97, c-1500. Mine was making a lot of noise. The carrier broke where the bearing mounts to the collar. For a long time, I wanted a LSD, so here was my chance. I went with an Eaton truetrac. Im very happy with that. It has helix gears in it, instead of clutches. Truetrac is a grate choice for the street. I also went from 342s to 373s. 373s are a grate choice for small tires. Im running 275/60-15s. You will loose a little MPGs, and the RPMs are about 300 or 400 higher. The truck does pull better and launch better. I changed all bearings and seals. I did all of the work myself with some help from the lead machinist at our shop. It cost me about $1200, but I now have a new rebuilt rear end with LSD and 373s.

Kiko_Jones said:

Thank you for the quick reply. It's a 2wd with a 10 bolt with a 4.3 V6
Can you talk to me more about the 3.73 upgrade? I'm planning on a 4/6 drop. I use it to drive to the Home Depot for Mulch and other non-sense.

Click to expand...

Well the upgrade is easy just find a axle with a 3.73 axle already under the truck at the pull apart

Since I can't seem to find a definitive answer for the questions I seek, I am either going to build a GM 10 bolt or swap in a 14bsf, either will have 3.73 gear. I was able to get tube flange to tube flange measurements for both from work, but not able to get WMS to WMS. There is a ~6.5" width difference over all or a 3.25" per side width difference from the 14b housing to the 10 bolt. My reasoning for wanting to do the swap is to handle power output of say 500+HP, both axles will be a full spool, with the biggest axle shafts I can find and in the 14b case will have custom 5x5 shafts. I wish I could just find a 454ss 14bsf as it would be a direct swap. So I guess my biggest question is will the 10 bolt handle 500+ hp or should I just start looking at say a Ford 9" swap like @Wh4t3v3rs did?

MrPink said:

Since I can't seem to find a definitive answer for the questions I seek, I am either going to build a GM 10 bolt or swap in a 14bsf, either will have 3.73 gear. I was able to get tube flange to tube flange measurements for both from work, but not able to get WMS to WMS. There is a ~6.5" width difference over all or a 3.25" per side width difference from the 14b housing to the 10 bolt. My reasoning for wanting to do the swap is to handle power output of say 500+HP, both axles will be a full spool, with the biggest axle shafts I can find and in the 14b case will have custom 5x5 shafts. I wish I could just find a 454ss 14bsf as it would be a direct swap. So I guess my biggest question is will the 10 bolt handle 500+ hp or should I just start looking at say a Ford 9" swap like @Wh4t3v3rs did?

Click to expand...

The three main reasons for my swap were..... 1) power handling 2) quick change of gears 3) if I break an axle at the starting line i can still roll my car on to a trailer. C-clips are undercover Karma for all the power braking as a kid!!!

Does anyone have the correct part numbers for the left and right spring plates for the 14bSF? Aka the plates that go on the underside of the axle with holes for the U bolts

Postmech said:

Will the differentials out of a 96 k1500 Suburban (at pullapart) fit a 98 k1500 extended cab? My 98 has 3.42 gears and the 96 has 3.73 gears and larger rear brakes. Both have standard suspension. I am going to church but I will check for reply when I get home

Click to expand...

Yes, there is no difference. Just make sure you have both the 3.73 front and rear diffs installed.

thanks for the info

Mike said:

Post here if you have a simple question. This will help keep track of common info and reduce clutter.

Click to expand...

OK here's one. I have a 1971 K20 4x4 with what I believe has a Corporate 14 bolt simi float diff that has some real drive line slop issues. I have access to a 1989 Chevy Suburan V 2500 4x4 with a good rear end that I believe is also a 14 Bolt. Any one know if the mounting points - leaf springs - are the same size/width on the axles? Did the frame widths change over the years? Can I just switch them over and they will bolt up in the same place?? Assuming they are the same width. The 89 to the 71 ( which I believe is not the original axle). If that is the case - I think the 89 uses metric brake lines so I would have to convert the 89 hoses to the 71 hoses or vice versa - or at least one end of them?? Probably have to use the 89 Calipers??? Also will I be able to do the same switch for the front end 89 diff - 10 bolt to replace front Dana 44 big hub . I believe both have 4:11 gears - but I know the 89 diffs are original so it might be a good idea to keep them together. Any thoughts would help. I'm hoping to not have to pay big bucks to rebuild the 71 axle since I have the 89 V2500.

The spring perch widths are different. Look for a 1 ton, they have the same perch width. Shock mounts most likely need to be changed, i haven't messed with a 67-72 so don't know. I the hoses are prolly metric, parts store website would tell you what they are. Does your front axle has discs? If so then don't have to change a thing, the calipers will bolt on to the 10 bolt.