Front Diff shot??

I just picked up my truck and noticed that the tire sizes were different. I don't know if the difference would destroy the Front diff or not, but I just started getting a clunking coming from the front right of the truck when I am driving, and it seems to get worse when I brake. It is either the front diff or the hub bearings. Getting it on a lift on monday to find out, anyone had the same or similar problems, or know if this combo is too far off?

Specification Sidewall Radius Diameter Circumference Revs/Mile Difference
255/50-16 5.0in 13.0in 26.0in 81.8in 775 0.0%
245/50-16 4.8in 12.8in 25.6in 80.6in 786 -1.5%

diameter is only off less than a half an inch, idk :roll: I love these trucks.
 

gjp

another post whore
Re: Front Diff shot??

I thought different tire sizes will mess up the Transfer case and not the diff.
 

big gear head

axle builder
Re: Front Diff shot??

The front differential is a standard differential and will not be damaged by different size tires. If it was a limited slip differential then it might cause a problem, but it isn't.
 

gjp

another post whore
Re: Front Diff shot??

Lots of guys neglect the oil. When I bought my truck the oil I sucked out was black sludge. I had a leaking outer seal. I was able to flush out most of the sludge and put in fresh oil.
 
Re: Front Diff shot??

gjp said:
Lots of guys neglect the oil. When I bought my truck the oil I sucked out was black sludge. I had a leaking outer seal. I was able to flush out most of the sludge and put in fresh oil.

Thanks, I will check it out when I get it on a lift on monday. :tup:
 

big gear head

axle builder
Re: Front Diff shot??

Yep, lack of oil or bad oil is what causes a lot of them to go. Many people never check the oil in the front.
 

swoop

under contruction...
Re: Front Diff shot??

yea lack of oil killed mine. previous owner was a moron and was totally oblivious to what was actually happening. well a few weeks later and leaking oil it chewed the front diff to pieces. now its my problem.
 
Re: Front Diff shot??

Tons of play in the shafts, the Front Diff is shot, ughh. Anyone know if they are the same from SY to TY, I have to pick up a new one. I love these trucks. :tup: Also if anyone has one for sale let me know, I posted in the WTB section, but it couldnt hurt to post again. Thanks for all your input guys, much appreciated.
 

'JustDreamin'

Dream: 6LV8 Turbo Bravada
Re: Front Diff shot??

The front diff assembly is pretty much standard 4wd S10 hardware.

However, there are some potential differences:

The pass side tube is specific to the Sy / Ty / Bravada, in that you can't disconnect the Pass side axle.

The axle ratios need to match what you're running in the rear (which may be tough to locate, hard to say)

Newer cases (out of 2nd gen trucks) are said to be a bolt-in deal and have a drain plug so you can actually change the fluid. Might be a worthwhile upgrade since poorly maintained fluid is a definite killer. I don't have any hard firm data on whether they are identical or not, nor do I know when the drain plug provision was added (model year range). Maybe one of these other guys knows for certain.

'JustDreamin'
 

'JustDreamin'

Dream: 6LV8 Turbo Bravada
Re: Front Diff shot??

I'm pretty sure the Sy's and Ty's both run 3.42's.

For grins, I checked out Car-Part.com. Searched for a 1999 S10/Blazer with 3.42's and auto. Got 36 pages of results, with prices in the $100 range for complete units.

A late model S10 or Blazer will likely have the disconnectable front passengers side shaft which will be different than the one you've got now. But you can lock it in place (for full time 4wd) or use your parts (if they're any good) or search for a comparable year Bravada (which is full time).

'JustDreamin'
 

big gear head

axle builder
Re: Front Diff shot??

Yes, all of the S series trucks used the same basic front differential. The only differences is in the right axle shaft and tube, gear ratios and yoke. The SyTy uses a companoin flange instead of a yoke, which all of the 4X4 trucks use. You will have to change the yoke and right axle shaft and tube. It's been a while, but the last time I talked to Rob Gordon at DTS he said that they had a drop out from a Sy for sale.
 
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