Rear End

[klb76]

Well I think I am finally going to take care of my rear end problem. My intention is to have the original 3.55 rear end rebuilt. However I really don't want to have much downtime on the car because by the time I get to start working on the car, it is going to be summer and I wanna drive it. (college) So what I am thinking is I am going to buy another rear end, and either have it rebuilt or buy one in good shape and have the original rebuilt. What my question is, what years will fit the 76? I read somewhere about a smaller yoke or something like that on earlier years? Does anybody have any recommendations on someone to rebuild my differential that is easy on a college guys wallet?

klb

 

[JonM]

Why not just buy a rebuilt unit, pay the core charge...then send it back when you change it out? You can buy a fully rebuilt unit at Ecklers 1965-79 3:55 for 889.99 You could most likly get it for a better price if you searched around.

 

[klb76]

That is exactly what I would do if I had 900$ + shipping... but if I drop that much right now then I am going to have to wait to finish paint and stereo system (which of course are both half done) I do have a job here at college but it only pays me around 500$ a month so my budget is oh so small. If I just get it rebuilt from a local guy I am thinking it is going to be around 300 plus parts, but I really hate to trust a local yocal guy. Any ideas of anywhere less expensive then Eckler's?

klb

 

[MidShark]

klb76- I've seen them advertised by Bairs for $495 w/exchange -814-683-4223. Chicago Corvette-$425/exchange-708-458-2500
There are others.
Dick

 

[klb76]

I will definitly check those companys out. That is definitly in my ball park! Thanks for the lead

klb

 

[427SB]

ebay, ebay, ebay... Just an example -

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33731&item=2404936151&rd=1

 

[klb76]

HAHA yeah I definitly have my watch list on Ebay full of corvette rear ends. Which I guess brings up my question again, what year rear ends are interchangeable? Isn't there something about the yoke being smaller on some years?

klb

 

[SolidLifters]

"Isn't there something about the yoke being smaller on some years? "

No.

 

[Stingray6974]

65-79 are the same. 63-64 use a coarse spline yoke.
Two important things to remember about the $495 rebuilds. They do not include new gears or side yokes. I do the exact same rebuilds for $375 except I use only Timken bearings and Eaton clutch packs.

Mike

 

[klb76]

Hey Mike
I think you are the one who helped me diagnose the problem in the first place awhile back. I am almost positive it is the rear end now, I believe something with the pinion bearing. I replaced all 6 U-joints a couple months ago and the problem got better but now it is downright scary riding in the car. Under WOT there is no abnormal vibration or noise, but under deceleration around 70 mph the car just vibrates like hell and makes what I can best describe as a whirring/growling noise. It is to the point I don't feel safe with passengers, which might be mostly because I embarrassed.... But anyway... what do you think I will need to replace as far as parts? I hear that the side yokes from the factory weren't so great so I will probably have to replace them right? What kind of price do you think parts will run? I don't mind spending the money to have it done right. I might leave the rear end in to drive the car to the paint shop over spring break, but first thing after I finish this semester the rear end is gonna need done. Hopefully you can take a customer

klb

 

[Stingray6974]

rear view

 

[Stingray6974]

klb,
First thing check your rear end grease. Then look for grease leaking/slinging from the pinion seal. Grab hold of the driveshaft as far back as you can. Try to move it up and down while watching the pinion yoke for movement. Any play is bad. If there is movement you are risking at least damaging the gears up to explosive destruction of the rear end. Muskegeon has the lowest price on yokes that I know of. However I have had end play vary as much as .020. But that is still quite acceptable. New gears run around $200-$225. $375 covers everything that normally wears out in the rear end including labor. Carrier, side gears, and pinion gears would be extra if they needed to be replaced.
Is the vibration when you de-accelerate the same problem as before or did it start after replacing the u-joints?

Mike

 

[klb76]

Well it started as just a vibration between 55 and 60 mph... then I checked all the U-joints and two were pretty bad, so I had all 6 replaced when it was in the shop because I was already dropping the tranny for a new shifter. So after that, on the way back from the shop had a situation that put the car off the road for a couple weeks. By the time I finally got a chance to drive it the vibration seemed to be less but it was still there. Then the gap between 55 and 60 went to 55 and 65 and then anything over 55 and now it is just unbelievable around 70 mph. The vibration is very similar to when my brother's mustang had an out of balance driveshaft, and it was way out of balance, half was missing. Really from what I can tell there is no play side to side, (side yokes). When you say grease the rear end, I assume you mean there is a grease fitting at the front of the differential? I did drain the rear end, re-fill, and added posi additive when the U-joints were replaced. I will check to see if there is any play in the driveshaft next week when I go home.

klb

 

[Stingray6974]

klb,
I was referring to the grease (lubricant) level in the rear end. Check the u-joints very closely. Make sure they are seated in the yokes. Also check the bolts holding the halfshafts to the inner and outer yokes. It sounds like you have a serious problem.

Mike

 

[Tifton81]

Same Problem

I need help also....I had the same problem with vibration on my 81. It had a really bad roar and vibration at about 60 - 65mph. So, in December, I purchased a rebuilt chunk from ZIP products out of VA. I was going to purchase it from Ecklers, but then I found out they get their rebuilts from these guys and charge an extra $150.00 for them. Anyway, I had the chunk replaced, rear leaf spring, all bushings and all six u-joints. The car rides alot better, no noise now but I still have a little vibration around 65 - 70 mph. What can it be??? HELP

 

[klb76]

Oh man... isn't that life huh? I hope I will be able to drive it enough to get it to the paint booth and back, I already have a date for the painter and everything. If worse comes to worse though I will flatbed the thing down there. When I get home I will get it in the air again and try to locate my problem for sure. Let me get a quick checklist here.

- There should be no movement where the driveshaft meets the differential.
- There should be minimal play in the side yokes
- Check all U-joints
- Check bolts from half-shaft to side yokes

Anything I am missing? This project seems to be moving up the priority list everytime you write back Mike

It sounds like you have a serious problem.

klb

 

[Stingray6974]

Close. There should be no movement in the yoke on the front of the differential when you try to move the driveshaft up and down.
Don't worry about in and out play from the side yokes on the diff. That will be taken care of with the o/h.
Make sure the u-joints are seated in the yokes and that there is no play in the joints.
Checks the bolts on the halfshafts. The four 5/8 bolts on the outer end holding the halfshaft to the trailing arm spindle.
Somewhere something is coming loose.

mike

 

[Stingray6974]

Tifton,
Try to figure out when it is worse. Cruising, accelerating, or decell. Drive it at the speed it vibrates the most, put it in neutral and let of the gas. See if it changes. Run it up to 80, put it in neutral and shut off the engine. See if it comes and goes. Try doing different things to make the vibration change.

Mike

P.S.
A common vibration is a sagged trans mount.

 

[Yoda]

Tifton,

I hesitate to mention this, but... make sure the tires are balanced and the alignment is check too. Do the tires show any unusual wear patterns?

I :BOW to my ole friend Mike (Stingray6974) when it comes to knowing his STUFF about Corvettes. He's helped me more than a few times
Just thought I'd throw my .02 in

Bud

 

[Tifton81]

Thanks Mike and Bud....I will do just that. If the weather is good, I'll take it out and check the vibration at different speeds. I'm also going to put it up in the air and check the transmission mounts.

I'll let you know what happens.

Thanks

Tifton81