I have a GMC 1990 454 one ton 4WD.

Question:  I have a question on my SM465. When I try to shift into reverse it feels like I'm pushing the shifter through carpet and when I can finally get it into reverse I lose all other gears none of them will remotely engage. And to get it into the forward gears i have to pull the shifter assembly and manually pull it out of reverse. Would you have any input on this? How much would it cost to repair this or should i just buy a new trans?

Answer: It sounds like the rev fork plunger has came out. There should be a retaining clip on the rear of the rev fork plunger… this can be fixed by taking the top cover off and taking the rev fork out, compressing the plunger and welding a steel washer on the back side.We can do it for you your cost would be $45.00 plus shipping you will need to send in us your cover.

Give Scott a call toll free 888-824-2012 he can help you.  You can see the other parts we can provide for the SM465 on our site.