Manual Trans Shifts poorly at Temp

[truckeejeeper]

Hey Y'all - So my 1991 5-speed sport has been shifting poorly when it gets up to temp. (210) When I first hop in, it gets into gear like a breeze, but at 210 and really more so after its been running 20 mins or so and everything is heated up, it starts to get hard to shift, all gears are not great. I have to kind of wiggle and force/baby it in. It kind of resists, then goes in. I'm currently using Redline MTL 70w-80. My clutch is about 9 years old, I'm thinking that will be the next thing to go. But it shifts great when cold..? I drive most of the time in the SF bay area but large amounts of winter time in lake tahoe area/cold/snow etc.

Any ideas?

Thanks

 

[Tbone289]

Typically speaking, man trans. problems aren't going to affect all gears at once. It's possible, but unusual in my experience. I think you're on the right track with the clutch. I would suspect the slave cylinder. Have you bled/replaced the fluid in a while? Is the release point close to the floor when warmed up?

 

[truckeejeeper]

The fluid is about 3 years old. The clutch is a bit "soft." But it works perfectly when cold.. thats why I'm thinking it's not just clutch yet... Am I on the wrong track? I worried maybe I have fluid which becomes a problem at temp. Or something else, I really don't know. What mechanically would make the clutch itself work poorly when hot? Thanks thanks

Oh I guess while I'm at it, recommendations for new clutch packages would be helpful too. I'll prob replace in next year. It's a stock 1991 4.0 5speed sport 4x4. Thx!

 

[Tbone289]

I should explain myself better... When I say "clutch", I don't just mean the clutch plate, I mean clutch plate, slave cylinder, etc. The point I was trying to make is that you may have an issue with fluid, slave cylinder, or air in the lines. That's why I asked how long it had been since you bled the fluid. I've had slave cylinders go bad in other vehicles in the past though, and that usually showed up as poor shifting/clutch release when cold, and improved with increasing temperature. So, I may be off base.

 

[sinat01]

I run a standard duty LUK clutch off rockauto. its been good so far. They make a heavy duty kit also. but I would start with the clutch and go from there. I run redline MTL in my trans and it doesn't give me any issues what so ever

 

[cruiser54]

Suck the fluid out of the clutch master.
Refill it and bleed the clutch system until clean fluid comes out.