So, I bought this 1987 F250 with a 6.9 diesel a c6 automatic and a 10.25 sterling axle with 4.10 gears, it is a good strong truck that so far has handled every load I have hauled with no problem but lately when the truck is up to operating temperature and I stop somewhere it acts like it dont want to go into drive when I leave also if I have parked somewhere where I have to back out and then put it in drive it is much worse than if I can pull straight out of the parking space. So far I have replaced the modulator valve and changed the fluid and filter, the fluid and the pan were both very clean and there was very little metallic debris on the magnet in the pan but it was due for service, also I have hooked up a pressure gauge and the pressure was about 10psi below specification in drive only, reverse and neutral pressures were at or slightly above specification. I should also add that this transmission is a remanufactured unit with about 32k miles on it and this problem didnt start until the weather got hot but that could just be a coincidence because the cooler temp has never been more than 210 degrees as measured with a blue point infrared thermometer. Other than this the trans has no issues at all so I am trying to figure our whether I can fix this trans or if I should just buy another one. Thanks for any help or info anyone can provide!

 

Those are the symptoms of worn out forward clutch seals.

 

Thats pretty much what I figured. So would I be better off tearing it apart and replacing all the seals, gaskets, and o-rings since it only has 32,000 miles on it or I can get another reman unit with a 3 year unlimited mileage nationwide warranty for about a thousand bucks. Also if I rebuild it can anyone recommend a good quality basic rebuild kit? Thanks for any help!

 

I've used several kits from Home - Transtar Industries