My 1994 22RE MT 2WD Pickup seems to be slipping a little in gear (under load or when I accelrate rapidly), but I don't spell that unmistakeable stench of burning clutch. The clutch/pressure plate, bearings, etc. have a little over 100k on them so I'm inclined to believe that they should be replaced regardless, but the truck itself has over 220k so I was wondering if the problem might be in the differential instead?

Can someone educate me on how to differentiate between a worn differential vs a worn clutch? Do differentials typically fail at high mileage?

The master and slave cylinders seem to be working ok and I don't see any leaking hydraulic fluid or gear oil.

I've changed the tranny and differential fluids every 30K since I've owned the truck if that matters.

Thanks.

 

Do you have a tach? How do you know it's slipping? If it's the clutch drive in a high gear (5th) at low speed and mash the gas to the floor, if the clutch is good it will hold, if not RPMs will rise. Also with a slipping clutch you won't always smell it burning.

 

Thanks Jason. No tach. I'll try the 5th gear approach. I'm not 100% sure the clutch is slipping, but under load in 1st gear I'll (sometimes) get an audible engine speed increase without a corresponding vehicle speed increase.


Is there any way to test just the differential or do I have to remove and visually inspect?


I've read some posts about the clutch pedal bracket breaking, but those posts are always regarding 4WD and a failure to disengage rather than slippage.

 

That's strange if it seems to slip in 1st gear, the way it works is it's harder for the clutch to slip in a low gear, like 1st, due to the ratios. There isn't anything in a differential that would cause a "slip" assuming your getting traction to both rear tires and not spinning of course. Has the truck always done this or started recently? How long have you had it?

 

Its the clutch, I would say your just not getting it hot enough to burn yet.
There is a possibility the diff could be bad, But that would mean it has been replaced with a locker or LSD and its gone bad.
The stock open diff slipping would be horrible grinding and popping and not mistakable.

 

It only started about a month ago.


The differential is original Toyota stock and it's not clunking or grinding that I can tell. The reason I question whether it's the differential is that I had a Datsun B210 many years ago that exhibited similar slippage that I ignored for a year only to one day be unable to drive the car because the rear wheels would no longer spin. It turned out the gears in the diff had worn to the point that they were no longer engaging the drive shaft pinion. I was hoping that this was just the result of poor 1970s Datsun metallurgy (or never having changed the diff fluid) and something that didn't effect a well maintained Toyota truck.


Thanks for the advice. I guess I'll replace the clutch (like I said it's old). I was planning on using an Aisin disk and pressure plate unless you feel strongly about buying direct from Toyota or another aftermarket brand. Let me know your thoughts. Thanks again.

 

I always like using a factory toyota clutch , pressure plate and throw out bearing.
The toyota disk seemed a little bigger last time i did one a number of years ago.

To learn how a differential works watch this . Very simply put and its from 1937.
Enjoy.

 

James, Thanks for your recommendation and video. Not a lot has changed in basic differential design in the last 77 years.

 

What did the slipping feel like? I'm having some issues as well and I am not sure on the culprit... Last night driving home I felt something quickly grabbing and releasing as I accelerated in first gear, second, and third. felt like my wheels were quickly slipping and then finding traction. But I know my 22re could never spin the wheels in second and third haha. Just curious if its the clutch, diff, or wheel bearings perhaps?

 

Hi Jim,


I still haven't replaced the clutch because I'm not certain that's the problem. The truck slips after shifting some times and at other times it slips when it's under load like going up a hill. By slipping I mean the engine speed will increase, but the vehicle speed won't. I ordered a back pressure gauge to check if I have a restriction in the exhaust, but it hasn't arrived yet. I have also experienced backfire a couple of times recently and read that an exhaust restriction (i.e., plugged catalyst and/or muffler) can cause both backfire and clutch slippage so I want to rule that out first. My truck has over 220k miles and the cat and muffler are both original parts.

 

Hybrid have you verified with a tach that your engine rpm is increasing?

 

Where have you read that exhaust restriction causes clutch slippage? That makes no sense

 

Thanks for the replay hybrid. I also am confused how backpresure causes slippage

 

No, I don't have an integrated tach, but it's pretty obvious to my ear that the engine speed is going up but the vehicle isn't accelerating at all.


I read about the clutch slippage thing in a couple different places when I was trying to figure out how to tell if my catalyst was bad. If it's not against the forum rules to link, here's one site:


http://www.ehow.com/facts_7639107_ca...nsmission.html


Mods feel free to delete the link if not allowed and my apologies.

 

The link you posted is for an auto trans. Exhaust pressure does not affect a manual trans.

 

That thought crossed my mind too, but do auto trans have clutches? I thought they almost always used torque converters? The article mentions both clutches and torque converters so I assumed it meant both automatic and manual transmissions. Plus I read the same in a couple of different articles more specific to manual trans, but that was the first one that popped up when I did a search for something to post. I'm just looking for answers wherever I can find them.


Also, if the exhaust is restricted because of a bad catalyst or muffler wouldn't that make the engine work harder (i.e., apply more torque to the clutch) to achieve the same vehicle speed as an engine with an unclogged converter? If so I imagine that could cause the clutch to slip or at least cause a marginal clutch to slip. I have no idea if that's right for sure, but it seems logical to my limited intelligence. I do know that when my truck slips it's usually under load.


The back pressure tester arrived so I'll post back if I find anything unusual. Actually I'll post back whatever the results. Thanks.