Ok so my oil pressure gauge stopped working, so I replaced the sender, and all good there. Went for a test drive and the transmission was taking an incredibly long to shift from first to second and second to third. I checked the vacuum line on the intake down to the tranny and everything looks correct. Is there anything else that anyone can think of to look at? The trans only has about 30k on it and I had 0 issues until after I replaced the oil pressure sensor today. Maybe a coincidence but I hope there is something im missing! Any ideas would be appreciated.
CK5
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TH400 Shifting problems
- Thread starter K5-CJ5
- Start date
454Sub
5/8 ton status
Did you maybe unhook the kickdown on accident? Its on the driverside of the case. Right behind the shifter rod if memory serves. That, or your vac line might have a pinhole leak in it.
Im going to go double check the vac line, but if the kickdown was unhooked the TH400 will still shift, but would not downshift when you stomp on the gas. I haven't checked for pinhole leaks yet but will go do that shortly! Thanks.
400 has electric kick down. It won't affect when it shifts(unless you are wide open)
Vac modulator sees little vac and it will shift later. I'd start there as was mentioned.
Edit: if you pull the line off the teams(modulator) it should suck deccent at an idel. Is the shift firm when it does shift?
Vac modulator sees little vac and it will shift later. I'd start there as was mentioned.
Edit: if you pull the line off the teams(modulator) it should suck deccent at an idel. Is the shift firm when it does shift?
The shift was very firm when it shifted. That being said I checked the two rubber lines at both ends of the steel tube and they looked ok. I went ahead and just replaced the two pieces as its pretty fast and easy and it now shifts perfect! Even upon further inspection of the old ones they dont seem to be bad, but obviously they were....Thanks for the advice guys!
Did the inside of the piece next to the transmission look even a little wet inside? If so, the problem is coming back.
You have a pinhole in the modulator diaphragm and its letting transmission fluid swell the rubber hose.
If the hose is dry, then it was probably just a little hardened and not gripping the steel tube like it should.
You probably moved it slightly when fixing the oil pressure problem and caused a slight leak.
You have a pinhole in the modulator diaphragm and its letting transmission fluid swell the rubber hose.
If the hose is dry, then it was probably just a little hardened and not gripping the steel tube like it should.
You probably moved it slightly when fixing the oil pressure problem and caused a slight leak.
Everything was dry, and is functioning perfect now. I think the issues was actually the runner line on the intake side.
