Tranny problem? IDK?

[Zero Hero]

I have a 87 chevy that has the 4 speed with granny low and when I first got the truck about a year ago I would shift from 2nd to 3rd at about 30 mph now I need to shift around 20-25 mph without getting the rpms to high. I brought my truck to the shop last week for a hanging brake in the front drivers side. They replaced the brake lines that attach to the wheel because they said after years of turning the hoses break and let fluid through but not back. Would that be my problem, the brake lines again? or is there something else that could be wrong with it? Or am I just forgetting how to drive my truck?
Also when I start in 1st like I been doing since I got the truck its starting to have jerky motion when trying to get moving.
Any help is appreciated thanks!

 

[1987 GMC Jimmy]

I have a 87 chevy that has the 4 speed with granny low and when I first got the truck about a year ago I would shift from 2nd to 3rd at about 30 mph now I need to shift around 20-25 mph without getting the rpms to high. I brought my truck to the shop last week for a hanging brake in the front drivers side. They replaced the brake lines that attach to the wheel because they said after years of turning the hoses break and let fluid through but not back. Would that be my problem, the brake lines again? or is there something else that could be wrong with it? Or am I just forgetting how to drive my truck?
Also when I start in 1st like I been doing since I got the truck its starting to have jerky motion when trying to get moving.
Any help is appreciated thanks!

I could tell you things to check that aren't the gearbox, but I don't want to run you around in circles to cover up the fact that I don't know enough about the SM465 to be any help. Don't worry, though, I know some people.
@Georgeb @HotRodPC @bucket

 

[HotRodPC]

I'd say NO, the brake lines have nothing at all to do with this. The 1st gear jerky motion could be clutch chatter. A few things cause that, sometimes an adjustment if it's adjustable can help, sometimes a seeping rear main seal getting oil on the clutch disk can cause it, a few weak pressure plate fingers can cause it, and I've seen a couple that had clutch chatter real bad and when it was changed you could tell the clutch had been very badly overheated at least a couple times. You could see the heat check in the flywheel even.

So what do you mean you HAVE TO SHIFT at 20-25? So does it grind at higher speed than 25? Simply won't go into the next gear? Won't come out and hung up in 1st gear or what? Have you tried double clutching it at higher speed and did it make a difference when you did?

 

[Oldrider]

yes, please give a little more detail on exactly what the problem is.

 

[HotRodPC]

He Gone !!!

 

[74 Shortbed]

Probably solved his issues..

 

[Zero Hero]

Finally got back to th internet to check on this post.

It appears that my truck is back to normal after driving it for a couple of days. Have no clue why it was acting like that, it was fine when when I parked it. I only let it sit for 2 days over the weekend, maybe that had something to do with it?

 

[HotRodPC]

Thanks for posting back.

Is it possible you ran through some deep water or something? Maybe you got the clutch disk a little wet? Do you have an oil leak that could have got on the clutch disk and you've burnt it off now? Have you recently added any clutch fluid to the master? Maybe an air bubble in the system and you weren't getting a full push on the slave cylinder? If it happens again, I'd consider bleeding the slave/clutch master cylinder.