superex87

Hey guys I have searched around alot but havent found much information useful to my problem.

I have a 88 pickup, standard cab, 2wd, with 22r engine and 4 speed manual transmission.
Currently has 186k on it.

Story time.....

When I first bought it when driving at 50 mph I was getting a strong vibration from the rear end. I know it was not the front as the steering wheel does not shake with the rest of the truck. At slower speeds there was no vibration at all. I also was hearing a clank noise when starting off in first gear.

So far I have replaced....
-both rear wheel bearings, old ones had some play
-ordered a brand new open diff third member from marlin crawler, 4.11 gearing original was 3.09
-had a local machine shop replace the old u-joints with new ones

Currently I have installed all of the new parts and the vibration is WORSE then it was before I changed any parts. The vibration is now at 40 mph but the clunking noise is completely gone.

Is it Possible to install new u-joints incorrectly/ off center? I had a machine shop do it hoping they knew what they where doing......

The new third member is gushing gear oil where it meets the axle housing, I used a liquid gasket meant for oil and let it dry the proper amount of time. Is there a gasket that goes here?

Will a dent in a drive shaft cause it to be out of balance?

Thanks a ton for your time!

JustDSM

You shouldn't have the leaking.. Perhaps the coat you put on was too thin? I just regeared my 4x4 ('83) and put a good bead on there, just enough so when I torqued the nuts, it would lightly squish out.

The dent could cause an out of balance issue. It might be worth investigating..

My gut instinct is telling me the nut holding the output flange on the transmission could use some tightening. Get underneath the truck and try and wiggle the flange. Just push back and forth. Tightening up the output flange on my transfer case did wonders for reducing vibrations (same principal as what I suggest you do).

Give that a shot and let us know if you have any improvement!

T100cowboy

yeah you shouldnt have a leak at all. after you check the flange on the tranny I would look at the driveshaft. even a small ding can cause a bad vibration. If there is a good dent in it I would have it balanced and straightened or it will cause you issues.

(ask me how I no)

also If those all check out have your tires rebalanced by a good shop! tires out of balance can cause odd vibration issues at certain speeds sometimes.

fdp101452

I would take the drive shaft out and take it to a machine shop and have it checked. The only way I know of to check it properly is to turn it between centers in a lathe. Find out if they can do that before you leave it.

superex87

Well I fixed the leaking rear end, guess what happens when you forget one of the third member bolts......yup it gushed gear oil everywhere! So that is fixed.

I have traced the shaking to the drive shaft, after close inspection the freaking machine shop put a 2 inch dent in it!!!! Although there was already a small dent about 1 inch long in it I still am extremely angry but they wont do anything about it.

I have decided the right way to fix the problem is to purchase a new drive shaft, yes it will be expensive but in the long run guarantees it wont be a problem any longer.

Are the 4wd drive shafts tougher/ solid?
My drive shaft is extremely light weight, i.e. very thin metal tubing, is this normal?

T100cowboy

yea that sounds like your problem area then. IF you have a good driveshaft shop around its probably ALOT cheaper to have them fix it than to buy a new one.

Mine cost me around 50 bucks and it was a 2 piece driveshaft that had to have both straightened and balanced in a 1 ton dodge diesel.

Though I did take it out and put it back in so that saved me some of the shop rate.

My 4wd shaft is a solid one piece. I wouldnt worry about it being light have you seen what was in the 90's model 1/2 ton chevys?! their some kind of alum tubing and they held up fine for me. my dad and brother still have a couple with them too and havent had any trouble.

we were regularly hauling cattle in a 20 foot stock trailer with all three trucks. as well as hay and going off road to check cattle/feed

fdp101452

Find a good machine shop that will turn your yokes off of your shaft and reweld them to another tube. The truest way is to weld them in the lathe, but most shops wont weld in their lathes and I wouldnt weld in mine either. As long as the ends of the tube and yokes are turned true, you can weld it together on a flat bench then doulble check your work in the lathe.