Chris @ CK, any ideas on an early 1-2 shift

[68Camaro]

Chris,

I have been chasing a problem with my trans for a while now. Many on this site have been very helpful in trying to solve this one, but I still haven't figured this one out. I am hoping you can provide some input.

I have an 87 CZF 200R4 in a 68 Camaro with a stock 275 hp 327, I recently rebuilt the trans (did it my self) with stock components and a mild shift kit and boost valves from Bruce.

The problem I am having is my 1-2 shift a full throttle happens at 3500 rpms, but the 2-3 will hold to 5000 rpms. It will also down shift from 2nd to 1st and hold the 1-2 to 5000rpms. All the shifts are firm and there is no binding. Pressures are okay, but not as high as they could be with the larger boost valves, see below. I am not getting any additional boost in manual 1 or 2 which is where I think the problem is, maybe pump related?

Park: Min TV 70, Max 225
Rev: 125, 250
3-4: 70, 250
1-2: 125, 125

Any ideas on where to start or additional information I can provide to help solve this one?

Thanks,
Greg

 

[chris718]

hey i have seen this before .it sounds like the signal oil pipe on the valve body is missing or disconnected did you check it.?this oil pipe carries manual lo and d2 coil to the intermediate boost valve in the pump to raise pressure when the gear lever selects these 2 ranges .check first as this can effect other circuits by allowing oil bleed of from the pr valve.this is interesting lets see what we have .check and post .www.ckperformance.com

 

[68Camaro]

Chris,

Thanks for the response. The signal oil pipe is on the vb. Should I be checking for an obstruction in the tube or sticking valves at either end of the tube? The pan has been very clean, so I am not sure if this is a possibility.

Thanks again for your help.
Greg

 

[chris718]

no boost in manual lo or 2nd is oil pipe,obstructed or blocked holes in spacer plate ,misaligned gaskets on vbody or pump, .should not be hard to locate .if the boost valve was stuck or misassembled you woud have varios other problems .why dont you send us the body for testig .we can put it on the vboby dyno for an accurate diagnosis.also the vbody may have a mismatched ,broken or misassemble 1/2 spring or 1/2 vtrain problem .if i get the vbody im sure i can fix it or figure out the problem .car must be a pain to drive w/ 3500 rpm full throttle 1/2 shift .www.ckperformance.com

 

[68Camaro]

Chris,

You are right, this problem takes most of the fun out of driving the car. I think sending you the vb is a good idea. I will be traveling (work related) for the next 2 weeks, when I get back I will give you a call and set up sending the vb to you.

Thanks

Greg

 

[chris718]

talk to you then.www.ckperformance.com