The Stovebolt Site Forums The Parking Lot '60-'66 Trucks 1966 Rear End Replacement

I own a 1966 Chevy Stepside.
It has a 350 V8 and 700R4 as modifications.

I need to replace the rear end in my truck as the truck is vibrating like crazy at 60+ mph. The vibrations are so bad that i cant even see out the rearview mirror (please dont tell me to balance my tires--it's WAAAAAAAAY beyond that).

ok, long story (semi) short, i'm thinking it would be better to find a rear end in a salvage yard rather than fix the bearing in my rear end (which i think is the real culprit). Most shops in Houston repairing differentials want ~$900+ to do it. ugh! h#ll no.

Currently, the truck has 6-lug wheels and no power brakes. I am not fond of the 6-lug wheels, so if i can find a different year (with 5 lug wheels) rear end that will fit, that's fine by me.

So, what are my options?

The cheapest seems to be to find a similar rear end with 6 lug wheels. That way, i dont have to buy/find new 5-lug rims.

The next step up would be to find a (newer?) rear end with 5-lug wheels. Would i need a proportioning valve with this? (i "think" you only need a prop. valve with disc brakes, right??).

Right now, money is an issue, so i'm guessing that gonig with the 6-lug rear end is the way to go.

<sorry for the rambling>


my question is:
What other rear ends (truck or car?) will fit my truck? If i look at other chevy trucks (or cars?), what years should i look for?

I wouldnt mind finding a posi-trac if possible. =)

Thanks for your help,

Mechttu
Houston, TX

what bearing is it. it is not that bad to change the bearings as long as that is all that it is
ron

Yeah,putting in new bearings is a fairly easy job but make sure something else like bent axles or the like isnt your real problem.When I got my 68 c10 it had a very bad shake,felt like a bent rim or something like that so I jacked it up and ran it and the tires seemed to run true untill I got a closer look and relized the bend in the rim was matched up to fit the bend in the axle in such a way the tires turned true however the balance issue caused the bad shake...just a thought hope it helps..(btw ive been told some chevy nova diffs will bolt rite in)

the bearing just behind where the drive shaft bolts onto the differential, i'm thinking.

your thoughts?

nothing is bent back under there.
this all started happening recently--i was told a long time ago that my differential input (tail end of driveshaft) was loose and that i should think about getting a positrac.

3 more questions:

1) what year Chevy Novas should i look for?

2) Does anyone have a link (or source) on how to change out these bearings? I'm not scared to break off the differential cover (been there, done that to determine my gear ratio).

3) Anyone know a surefire way to determine if i have a positrac differential? what should i look for with the differential cover off?


thx,

mechttu
houston, TX

get yourself a copy of the 63 and the 66 chevrolet truck shop manuals..They will tell you all that is necs. If you plan on keeping this truck they will help you immensely
ron
replacing the pinion brg and seal + the other brgs will be less expensive than replacing the complete rear axle. you also may need a speedi-sleeve for the pinion shaft where the seals runs on it due to wear from the seal-eliminates seal leaks

A quick thought, you say that you are running a 350 with a 700R4. I to have this combination. Sooo, it would seem to me that your drive shaft had to be shortened. Are you sure that it is not out of balance?

Beyond that I also installed a rear end out of a 71. They bolt right in with one change. Can you weld?
The panhard bar bracket on your 66 rearend needs to be removed and put on the donor rear end (there are specific steps for this). (I believe a rearend from a 67 to 72 will work and only need this mod) (73 and up needs the trailing arm brackets relocated as well)
This will give you 5 lugs.

yes. my drive shaft was replaced--this past March.

the vibrations only started a week or so ago...

I just had my truck in the shop thinking I had bearing trouble. They installed a new transmission mount and solved the problem.
Take the truck out where the is not much traffic, get it up to speed, put it in netural and shut the engine down. If you have not vaberation I would check the trans mount, or you might just check the mount.