When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hey all, I've got a 1976 Toyota Pickup and I had a clunking issue when going in reverse and the wheel full lock left or right. The wheels will skip and jump which has been tearing up my tires. I drained the oil and it was full of metal shavings so I assumed the rear diff was toast. PO gave me a spare diff so I figured I would throw it in. I had two problems right off the bat. First is one of the studs needs to be super long on this new diff. No big deal as the diff actually came with the super long stud. The second problem is the flange holes don't quite match up with my drive shaft. I think my options are pull the flange off the old diff and swap it on or drill new holes on the new flange. Does that sound right?
Do you know what the "new" diff came off? I'd sure want to know more about it, like its gear ratio.
Not sure what people do in this case, but I'd be hesitant to drill more holes in the flange. Might not be a big deal, but it would suddenly have a lot more weak points with all those holes.
Unfortunately I've got no idea. PO said it was a replacement but I'm not able to get a hold of him anymore to confirm. Internals look the same but I didn't count teeth or anything. I also don't have the tools needed to check preload or backlash.
Yeah two wheel drive. OK so the weird thing is the diff looks good to my untrained eye. I'll post some pics when I'm off work but I imagine I am looking for is uneven wear or gouges on the rack or pinion gears? I turned the flange and it seemed smooth. I was starting to second guess my diagnosis but metal in the oil can't really mean anything else right?
Powder-sized metal shavings in the oil is completely normal, and why the drain plugs are magnetic. Chunks or any large pieces is not normal.
Hope you have a good way of drilling through that metal! It won't be easy, necessarily.
I'll be interested to hear if the new diff fixes your issues.
Hmmm well damn. If its not the diff any idea what else it could be? The bearings on the rear hubs have a little play. I was gonna replace them as well.
It depends. Hard to diagnose over the internet. Even if the metal shavings are normal, that doesn't mean the diff is fine. Clunking can just as easily be u-joints, or broken transmission mounts.
How did the axle shafts look?
The rear tires skipping sounds like what would happen with a locking differential, so your line of thinking is right. It's just hard to say, especially since different people feel different things depending on what they think the problem is, and we can't feel/hear anything from the internet.
What I see as "normal" wear in the gear boxes of my 98 is very fine metal shavings covering the drain plug.
The brakes can definitely "grab" if gear oil is soaking the pads. You didn't mention the skipping/jumping only happening with braking so I didn't mention that possibility.
It doesn't happen when braking. If I'm in reverse and I turn the wheel full left or full right the whole cab shakes (only when moving) and I can hear the wheels skip and skid. So here's the thing... I just examined the differential I pulled off and its welded. I had no idea as I've only had the truck for a year. Would the welded diff cause that? I imagine it could right? Rear diff Rear diff two
Decided not to drill the flange, I have a feeling I wont get it square and then i'll have other problems. I was hoping I could swap the gears from one housing to another but it looks like I would have to basically rebuild the diff at that point. I don't have the tools to do the job so I would have to have a shop do it. Am I just better off sourcing another diff from a junk yard? Maybe if I sell off the other diffs I can break even?
With 4x4s, there are a lot of spare parts laying around. With a truck as old as yours and 2x4, it might be harder. When I replaced the rear diff on my 83, someone sent me the part for free. I just paid shipping. So yeah it's possible if you're willing to search around a bit. I found it either on this site or the Marlin Crawler site. I don't remember anymore if 2wd gears are the same as 4wd for that year. If not, it'll be harder. Not sure if it's still up and running, but for a while there someone had a long thread going on Marlin's classified area, selling parts from an all-Toyota junkyard. I found a ton of obscure stuff for my 83 through that thread.
Looks like the welded diff is a 4.1 and the open diff is 3.07. I am running a 4-speed 2wd with 14" tires, seems like 3.07 would be a much better fit. I found a guy down the street who works on diffs. I'm gonna see if I can have him either swap the gears between housings or the flanges, whichever is cheaper (I'm guessing flanges).
Sep 30, 2019 | 08:15 AM
