Topic: slack in rear differential

[whatitdo430]

I just got a 1987 toyota pickup and I'm kinda going through it and making a list of things to replace...I was looking at my u-joints and grabbed the rear driveshaft and it has almost 3/4 of a turn of slack in it....new to this so any help would be appreciated. also it is a 87 and has a carburated engine....I'm guessing it has been replaced??

[Duffil]

not necessarily...carbs were available up until 88 IIRC.  I don't see how it could have that much slop and still drive.  It would have to be missing 75% of the pinion teeth...Possible your ujoints are totally shot, exaggerating what you're feeling?  try to isolate it, meaning put the trans in gear, ebrake on and spin the shaft. watch the ujoints as well as the pinion flange and double check where your movement is coming from.

[Tallchevy]

not necessarily...carbs were available up until 88 IIRC. 

I don't know about that. I friend of mine had a 91 standard cab 2wd & it was carb'd  I thought the same thing you did 

[MiniSimp]

It would have to be missing 75% of the pinion teeth...

Or the backlash is way messed up...

[jmsdad]

I don't know about that. I friend of mine had a 91 standard cab 2wd & it was carb'd  I thought the same thing you did 

Yep, carbs were still used til 91 or 92.  But only in base model 2wd standard cab---at least on the few that I've seen.

[whatitdo430 [OP]]

I guess I'm gonna pull it apart and see exactly whats going on with the rear end...How do I find out what gear ratio I have,  From what I've read this truck came w/ 4.10's but who knows about info you get from google...I may buy ring and pinion for front and rear. All I'm going with is 33/10.50's . Should I change gear ratios or leave them alone...I may go w/ bigger tires later so I dont know...thanks for the help guys

[MiniSimp]

I guess I'm gonna pull it apart and see exactly whats going on with the rear end...

Good Idea

How do I find out what gear ratio I have,  From what I've read this truck came w/ 4.10's

There will be a pink blob of paint on the end of the pinion if you do, you will be able to tell right after you pull the drive shaft.

I may buy ring and pinion for front and rear.

Don't go wasting your money yet, take it apart and see whats going on.

Should I change gear ratios or leave them alone...I may go w/ bigger tires later so I dont know...thanks for the help guys

If you're running 33's you should be fine, wait until you have 35's or bigger before you change the gears, it's expensive to do twice.

[Duffil]

Or the backlash is way messed up...

I thought about that, but damn, 3/4 of a turn...kinda hard to see it out that far, unless the caps are loose and he lost the locks.

 

[MiniSimp]

unless the caps are loose and he lost the locks.

That's what I'm thinking, otherwise if it was broken teeth there would be grinding. Without an actual measurement of how far it rotates, no way to tell without tearing it out.

[MiniSimp]

I just measured a properly set up 3rd and the furthest edge moves about 1/16"