TH400 problems
#1
TH400 problems
I'm having issues with my newly installed TH400. It doesn't seem to want to shift into second or third. First gear seems fine. But second it slips ALOT almost like its in neutral, but I feel some pull but not much. Third gear is non-existant. There is also a funky smell after parking the car. Like burnt tranny oil or something. I just adjusted the llinkage and pretty sure its right. B&M cooler 24k is installed. It doesn't seem to be heating up much which is good. Checked fluid level and is fine. The convertor is a Fuddle 3600. I wonder if this might be the problem and not the tranny.
Any ideas?
Any ideas?
#2
What I think the problem is....stuck, missing or leaking kickdown (detent) solenoid.
Ideas...the governor doesn't match the rear gear and or tire height. Vaccum modulator problem.
Maybe give us some details on this trans. If it's a rmvb it doesn't have a governor or modulator, or detent solenoid, etc. Need more info. Who built it? who installed it? was it calibrated for the application?
Ideas...the governor doesn't match the rear gear and or tire height. Vaccum modulator problem.
Maybe give us some details on this trans. If it's a rmvb it doesn't have a governor or modulator, or detent solenoid, etc. Need more info. Who built it? who installed it? was it calibrated for the application?
#3
Originally Posted by 8a8mfh
What I think the problem is....stuck, missing or leaking kickdown (detent) solenoid.
Ideas...the governor doesn't match the rear gear and or tire height. Vaccum modulator problem.
Maybe give us some details on this trans. If it's a rmvb it doesn't have a governor or modulator, or detent solenoid, etc. Need more info. Who built it? who installed it? was it calibrated for the application?
Ideas...the governor doesn't match the rear gear and or tire height. Vaccum modulator problem.
Maybe give us some details on this trans. If it's a rmvb it doesn't have a governor or modulator, or detent solenoid, etc. Need more info. Who built it? who installed it? was it calibrated for the application?
The one thing that keeps popping into my mind is that there was a little spacer that was on the end of the convertor when it was shipped to me from Fuddle. Did I need that? I took it off thinking that I didn't. I looked kindof worthless to me.
#4
Didn't install the spacer? I bet it has a vibration that changes with engine speed?
The last thing it could be is the converter not all the way in.
Sometimes it's hard to feel the shifts with a high stall converter, have you tried shifting well above your stall speed, say like 6,000.
The last thing it could be is the converter not all the way in.
Sometimes it's hard to feel the shifts with a high stall converter, have you tried shifting well above your stall speed, say like 6,000.
#6
Originally Posted by 408WS6
No vibration. So I need to pull the tranny and install the spacer?
A properly built LS th400 converter should have a long converter pilot WELDED on, it should look similiar to the stock one.
#7
Originally Posted by 8a8mfh
Is this an LS engine with a non LS converter?
A properly built LS th400 converter should have a long converter pilot WELDED on, it should look similiar to the stock one.
A properly built LS th400 converter should have a long converter pilot WELDED on, it should look similiar to the stock one.
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#8
What I'm getting at is this. The pilot on the front of the converter HAS TO go into the CRANK at least 1/8". Thats what some spacers are for, to extend the pilot or to bolt to the outside of the flexplate to extend the hole the pilot goes into.
It doesn't really matter what flexplate you have the bottom line is the pilot has to be inside the crank.
BTW this has nothing to do with the other issues you're having with the trans shifting.
It doesn't really matter what flexplate you have the bottom line is the pilot has to be inside the crank.
BTW this has nothing to do with the other issues you're having with the trans shifting.
#10
I edited a post up the page, not sure if you seen it. It refered to this.
What I would do is run it well above the stall speed and see if you can feel the shifts.
I have a RMVB TH400 in a '75 nova with a 438, it stalls around 3200 but it's real soft at low rpm, above stall speed it gets more firm.
Does your trans have a vacuum modulator? It's not needed with a manual vb but some builders believe it saves the pump by reducing line pressure at low engine loads. If you have one you can adjust it to make the shifts more firm.
If it doesn't have one then modulator pressure is at max.
What I would do is run it well above the stall speed and see if you can feel the shifts.
I have a RMVB TH400 in a '75 nova with a 438, it stalls around 3200 but it's real soft at low rpm, above stall speed it gets more firm.
Does your trans have a vacuum modulator? It's not needed with a manual vb but some builders believe it saves the pump by reducing line pressure at low engine loads. If you have one you can adjust it to make the shifts more firm.
If it doesn't have one then modulator pressure is at max.
#11
Originally Posted by 8a8mfh
I edited a post up the page, not sure if you seen it. It refered to this.
What I would do is run it well above the stall speed and see if you can feel the shifts.
I have a RMVB TH400 in a '75 nova with a 438, it stalls around 3200 but it's real soft at low rpm, above stall speed it gets more firm.
Does your trans have a vacuum modulator? It's not needed with a manual vb but some builders believe it saves the pump by reducing line pressure at low engine loads. If you have one you can adjust it to make the shifts more firm.
If it doesn't have one then modulator pressure is at max.
What I would do is run it well above the stall speed and see if you can feel the shifts.
I have a RMVB TH400 in a '75 nova with a 438, it stalls around 3200 but it's real soft at low rpm, above stall speed it gets more firm.
Does your trans have a vacuum modulator? It's not needed with a manual vb but some builders believe it saves the pump by reducing line pressure at low engine loads. If you have one you can adjust it to make the shifts more firm.
If it doesn't have one then modulator pressure is at max.
#12
Originally Posted by 408WS6
I don't believe it has a vacuum modulator but I could be wrong. But I think we are heading in the right direction. The line presure does have me concerned. What happens when the line pressure is at max? Does that make it not want to shift? Please excuse my transmission ignorance as I've always just taken these things for granted until now. I really appreciate your help