Fc-150 Rough Shifting Until Warmed Up

hello all.

I recently had a shop rebuild my FC-150 trans/T-case. it was leaking a lot, and I figure get it professionally done so it right, just for peace of mind.
since I got it back (almost a year now) it hasn't leaked a drop. HOWEVER....now its really rough to slide into gears until everything is warmed up, like 5 miles down the road, give or take. once its warmed up it shifts into 1-2-3 just fine. if i push the clutch in, i cant really downshift until the RPMS are matching, otherwise it grinds.

what causes this, and how do i fix this?

 

They might’ve put some insanely thick gear lube in there to help keep the leaks at bay. I’d drain it and fill with the recommended stuff. Let it drain overnight.

 

2x

 

reminds me of used car lots in the 60's and 70's . noise stopper

 

Is that sawdust?

 

Using sawdust would be wrong, wrong, I say!

 

pete sure that ones out of date , 1.35

 

I know. Last time I used it! It was a big deal when I was a kid but I never see it anymore.

Is STP even still made?

 

one of my uncles has a truck like that, but it's got a 10 speed from a large truck, so to be expected.

 

Refill with synthetic gear lube. If it doesn't leak the stuff does wonders. Available in both 75-90 and 75-140. I have not tried the latter but it is what will be going in the current D18 project.

 

I went to full synthetic gear lube in my Syncro VW years back. It started leaking in about 5 places. 3 months later, I drained it out and put GL4 back in. All the leaks stopped a week or two later.
I can't imagine the leaks in an old Jeep with full synthetic gear lube.
My Tux recieved some sawdust in the trans many years before I started driving it. Probably why the trans/TC need a rebuild a couple years later. That was a common "trick".
-Donny

 

You will note my caveat. Yes, the seals need to be perfect and the shim pack coated. And you still may get a little seep from the ends of the intermediate shaft. But I'll bet the shifting issue will go away with the stuff.

 

All right, follow up time. It's been over a year since I first posted about my issue, but life happens. I dealt with the awful shifting on weekends when I'd be up at the cabin. Then it was in storage from October until 2 weeks ago. brought it home and just looked at it.
Today was gonna take it fishing. Transmission was not shifting so enough is enough. Drove it around a few blocks to warm it up, drained it, put in the recommended 80w90, and blamo. Problem solved. Thanks guys

 

Lets hope it doesn’t start leaking again now that you have liquid gear oil in it!
The remote shift linkage in FCs leaves a lot to be desired.
-Donny

 

I have seen full synthetic do this. Most overdrives will not shift at all with synthetic 90 wt.