Intermittent vibration/shuddering in reverse

[bferguson1121]

I have a 1989 K1500 350tbi with a 700R4 that has been having an intermittent vibration or shuddering motion only in reverse.

No issues with moving forward but when it happens in reverse the truck will stop rolling backwards like it's in a bind and then I press the gas is when the jumping/vibration issue happens. When the truck is not experiencing the issue in reverse the it's smooth like normal. Also this issue has been happening going on 7 months now.

I have been under the truck and checked the driveshaft/U-joints and everything seems okay. However I'm far from an expert and if anyone has had a similar issue or any advice would be greatly appreciated.

I need to replace the kickdown or TV cable because it no longer locks into the bracket on the TBI but I don't know if that matters because the truck still shifts without issues.

 

[454cid]

I have a 1989 K1500 350tbi with a 700R4 ...I need to replace the kickdown or TV cable because it no longer locks into the bracket on the TBI but I don't know if that matters because the truck still shifts without issues.

I have never owned a 700-r4, but I suspect you have a transmission problem, not an axle or driveshaft problem. The kickdown cable is very important, and mis-adjustment can cause failure. I would not waste any time getting that fixed. Hopefully someone with more knowledge on the subject will comment and give more detail.

 

[Erik the Awful]

Check your rear brake drums. Make sure there are no fluid leaks and that your shoes are dry and clean. Adjust the drums and reassemble.

 

[thinger2]

You absolutely need to fix that TV cable.
It is really important to have that set up and working correctly on a 700R4.
You need to use a good cable and the linkage geometry and adjustment needs to be set at factory specs.
No bodging, no zip ties, nothing.
The Throttle Valve Cable controls line pressure amongst other things and a bad TV cable set up will fry a 700R4 fast.
Its a real well known problem.
I would fix the cable to spec, drop the pan and put a new filter in it.
And hope like hell it isnt smoked.
Dont drive it at all untill you try that first.
Trust me on this one. Back in the ancient times I roasted 4 of them before I figured it out.

 

[BOOT]

Trans mount?

 

[bferguson1121]

Just an update I have ordered the replacement throttle valve cable and I was wondering can I replace that without dropping the transmission. I can remove the transmission mount because its new but I would hate to drop the transmission. Also the intermittent vibration could be the rear brake drums because I have been fighting with the wheel cylinders leaking or the parking break seizing up. I honestly wish I could do away with the drum breaks but that conversion kit is expensive. Thank you again for the replies and I'm hoping replacing this cable won't be a big job.

 

[Erik the Awful]

Unbolt the TV cable end from the transmission case and carefully pull back on it until the hooked arm from the transmission is exposed. Hold it carefully with a pair of needle-nose pliers without bending it. Slip your old TV cable end off it, and slip on the new TV cable end. Bolt it down.

If you're struggling with it, you can drop the pan to see it from the bottom side.

 

[bferguson1121]

Unbolt the TV cable end from the transmission case and carefully pull back on it until the hooked arm from the transmission is exposed. Hold it carefully with a pair of needle-nose pliers without bending it. Slip your old TV cable end off it, and slip on the new TV cable end. Bolt it down.

If you're struggling with it, you can drop the pan to see it from the bottom side.

So with patience it can be replaced without dropping the transmission. The TV cable will arrive Monday and I will try to replace it. Thanks again.