Oh no! Transmission shudder.

[Coldpunk]

Background info: 89 k5 350/700r4 33's with 3.73 gears.

Truck had a vibration when i bought it, recently replaced my rear u joints and the vibrations went away. Now Im noticing that on the highway, when I'm in OD and I let off the gas and it shifts it vibrates really bad unless I either let off the gas completely, accelerate back up, or put it in drive instead of OD.

Im pretty new to both the site and working on my own vehicle in general and could really use some help figuring out whats causing this, and what I need to do to repair it. I felt both excited and accomplished after doing a tune up and changing the u joints myself. Not that I'm not mechanically inclined, I'm just new to working on vehicles. Thanks in advance -Karl

 

[Greg Ducato]

That could be converter clutch shudder you are feeling. If the clutch is glazed the shudder can sometimes be eliminated by adding a tube of "Shudder Fix" to the trans fluid. This is available from most trans shops, if you can't find it let me know and i can get you a tube.

 

[Chaddy]

Still sounds like drive line issues. You should get your DL spun. Did you inspect the ears? Did you put in junk U-joints?
Did you only do the rear?

 

[jeroundt]

What kind of shape is your slip yoke in? Does it move in and out of the transfer case smoothly?

 

[Coldpunk]

Driveline issues

Inspect the ears? No I did not. What do I need to look for?

I replaced one joint because it was shot, one of the caps popped off while driving. Luckily I was only a half mile from home so I limped home. I replaced the broken one first, then realized how idiotic it was not to have replaced the upper one as well while I had the driveshaft out so I replaced the upper a few days later. Both were replaced with the best quality oreillys had in stock. I believe they were precision.

When I pulled the drive shaft both times the slip yoke seemed fine. I need to change the transfer case fluid and check that as well(it's on my to do list this weekend). When I pulled the shaft I was prepared for some fluid to leak from the t case but none did.

I'll definitely try and track down some of that shudder fix. Should I drop the trans pan and check it for metal/replace the filter and do a trans fluid change before I try the tube of shudder fix? Or should I just put it in and see how it goes?

 

[Greg Ducato]

Just squeeze it in and test it out, should only take 1-20 miles to do it's thing. The cost is $10 or less.

 

[89GMCK5]

700R4 shudder

When I first got my '89 it was shuddering going into OD, or 4th as well. I read up on the 700R4 as I had never owned one prior. Through many internet articles I found that this is a failry common issue it seems. Nearly all of the "top" tranny guys recommended adding a tube of Dr. Transmission Shudder Stop or Shudder Fix, or something like that. I bought mine at O'Reilly's I believe and put it in. They all almost unanimously recommended adding a touch more tranny fluid than the dip stick indicates. Not a lot, just a touch. I did both of these things, my transmission level is maybe 1/16" to 1/8" above the "full" mark on the dipstick. The reason for the additional tranny fluid, I read, was because the 700R4 starves for fluid when in OD, and this contributes to the shudder.

I am by no means a tranny expert. So do your own reading and hunting across the internet, and make you own informed decision.

It worked like a charm for me. No issues since.

I don't think my rig was driven much prior to me buying it and daily driving it, so I'm sure that contributed to the issue to some degree. Like I said it worked great for the past year and a half.