Squarebody Differentials.

[boostdtalon]

Would the original build sheet tell me anything about what kind of diff's I have? My truck is 77' K-20 Camper special so I've been wondering what it came with. The only thing I can tell is that it has 4.10 gears.

 

[HotRodPC]

Would the original build sheet tell me anything about what kind of diff's I have? My truck is 77' K-20 Camper special so I've been wondering what it came with. The only thing I can tell is that it has 4.10 gears.

yes it should RPO codes for rear axles, GENERALLY, not always, sometimes H is used, but most often RPO codes starting with letter G will Rear axle related.

Yours should be a 14 bolt Full Float and it has 4.10's you know so the only other thing to know is if it's a Locking, LSD or Open Diff. I don't think Gov Lok started until 1980, so if it's a locking diff or LSD, I'm not sure what it would be.

 

[RetroC10Sport]

RPO G80 was still used for locking diffs before 1980.

 

[HotRodPC]

RPO G80 was still used for locking diffs before 1980.

While this is true, I'm saying the Gov Lok Unit wasn't used until 1980. So the G80 code have been an Eaton LSD unit or some other type. I'm not sure what was used before Gov Lock. G80 just means locking diff, doesn't specify which type or brand.

 

[bucket]

Pretty sure the Gov-Loc was used in the 70's too. Rear axle is a 14 bolt full floater and the front could be a 10 bolt or a Dana 44, it was a changeover year for the front axle. Early production was D44.

 

[HotRodPC]

Pretty sure the Gov-Loc was used in the 70's too. Rear axle is a 14 bolt full floater and the front could be a 10 bolt or a Dana 44, it was a changeover year for the front axle. Early production was D44.

I was thinking so too Andy, and it seems I seen an Eaton Demo on the Gov Lok video not long ago that said they started in GM trucks in 1980. No way to verify that but I just gave it credibility being it was an Eaton video. I know I've seen it in earlier models and figured it may have been a transplant or axle swap.

 

[boostdtalon]

yes it should RPO codes for rear axles, GENERALLY, not always, sometimes H is used, but most often RPO codes starting with letter G will Rear axle related.

Yours should be a 14 bolt Full Float and it has 4.10's you know so the only other thing to know is if it's a Locking, LSD or Open Diff. I don't think Gov Lok started until 1980, so if it's a locking diff or LSD, I'm not sure what it would be.

Ok gonna look into this but the RPO code says 7B GT5 4.10 for the rear.

 

[RetroC10Sport]

You might be able to find the axle code.

http://www.gmsquarebody.com/forum/showthread.php?t=4185

That will tell you more unless it's been swapped for something else in it's lifetime.

 

[HotRodPC]

Yeah, he edited it. If it's the RFN, I'd think that could be the axle code. Axle Code directly off the axle is best way. Of course that doesn't say if someone did a gear swap at one time either.

 

[boostdtalon]

That seems correct. The PO never said anything about the diffs being swapped.

 

[75Beast]

Squarebody Differnetials.

What type and how much fluid goes in a 1975 k10 front and rear diff?

 

[suijiaoki]

excent info

 

[RetroC10Sport]

Spammers are getting a little more sneaky...

 

[350runner]

Lol Banned

Sent from the dust in front of you!

 

[rumblebox]

Regarding the 14B FF and D44, do 3.08's and 4.10's use the same carrier?