Trans not building pressure

[Thomas veazey]

First start in the mornings my truck doesn’t like to go straight into reverse it has a turbo 350 and I bought it after I sat for 20 years so we figured a seal was going out so it can’t build hydraulic pressure it just acts like it’s in neutral then warms up and bumps into reverse don’t want to change out the trans yet any ideas?

 

[Poppy 87]

Welcome from Georgia!! After making sure fluid level is correct see if manual 1st (L1) engaged. They share the same clutch pack. After 20 years, probably needs internal reseal

Sent from my XT1254 using Tapatalk

 

[Bextreme04]

I would try dropping the pan and replacing the fluid and filter. I would hope you already did that when you put it back on the road after 20 years, but it had to be said. My TH400 was not happy with a parts store replacement filter when I put my truck back on the road after sitting. It would whine on cold start and took a few seconds of warming up before it would engage a gear. I had to go out and find the correct filter with a brass screen rather than the parts store one with paper media.

 

[Matt69olds]

Start with a fluid and filter change. Dropping the pan will give you a good idea as to how much life is left. If the pan is full of crud, plan on a overhaul pretty soon. The filter might be partially clogged with clutch debris.

Having said that, I have sen TH350 live with lots of trash in the pan. I recall one in particular that had a perfect outline of the filter, changed the fluid and filter and it was still working when he sold the car.

 

[JoeR Jr]

If it's a hard seal, and it sounds like it is, anything you put in there to soften the seal is bad for the clutches. Live with the delayed engagement or build it.
So you know, they can live an awful long time like that.
Joe