Ocasionally, mostly in the moring on my trip to work while the truck is still cold, when I try to shift into 4th the gears grind and it won't let me in. I have to put it back into 3rd and then try again. It is like the syncros just quit working for an instant. It only does this once then the truck is good for the rest of the day



Does this mean that my syncros are going out or is it just a trait of of the 4-speeds when they are cold?

I just put the tranny in and don't want to tkae it back out to re-build it.

 

I have never had a tranny do that to me, but, if it doesn't make a "howling" noise I don't think it would be muck of a problem. BTW what oil does it have in it?

 

Moved to proper forum

 

I think I put 140 wt oil in it.

and no it doesn't howl at all. except for in reverse and first but think that is normal for compound gears

 

try this: before you take off, go through all the gears before you let the clutch out, maybe that`ll line it up (just a thought)

 

I put a lighter gear oil in (75W) and it works great now.


I guess the heavy gear oil was not providing enough friction to have the syncros grab the gears properly. there were probally just slipping.


I can now even downsift into 2nd at a higher speed!!!!!

 

well now that is is below freezing it is doing it again.....so I have been letting the truck warm up for 5-mins before I drive and that has been fixing it but I wonder if my syncros are going out?

Also if it does sound like syncros is there an "easy" way to change them with the tranny still in the truck?

I pondered lifting the engine part way out......enough to slide the main drive gear out a little and taking the t-case off to pull the main shaft out a little..... anyone ever done this?