cal30_sniper
Active Member
I’ll try to keep this relatively brief, as I have a tendency to ramble with technical details…
I’ve been fighting an A518/46RH swap since the summer. Go #1 was an eBay trans I purchased for the swap that lost all forward gears within 3 miles of driving (drove home in reverse, which worked just fine).
Took it to a local trans shop with a really good rep. Got it back after a full rebuild (they never did say what was wrong with it the first time). Got it installed, set the Bouchillon Performance kickdown kit spot on with my factory Mopar Quadrajet throttle linkage, and could not get WOT upshifts. Shifted okay at part throttle, but would go to 6200rpm valve float at WOT without shifting. Shifts immediately upon lifting the throttle some. Would also 3-2 downshift at 90+ mph, going straight to redline.
Drove it back to trans shop and dropped it off. Despite asking them to diagnose the issue with pressure gauges, the “expert” technician replaced the valve body on his gut feel. They call me and tell me everything is fixed, and I go get the car. They also installed a TF-1 shift kit while it was apart due to my complaints about soft shifts.
Driving home, shifts fine at WOT, but softer at part throttle than any shift kit I’ve ever felt. It also doesn’t want to 2-1 downshift, even at low speeds. At this point, with WOT shifts working properly, I move forward with my MicroSquirt install to control OD and Lockup. I’m using a GM oil pressure sensor in the governor port and a MAP sensor to control OD and Lockup. Take it for a test drive to figure out what pressure I want to have the OD and lockup kick in, and notice an issue…
Governor pressure climbs fairly regularly until 32psi at 50mph (seems significantly less than 1psi per mph, but this is a truck trans in a passenger car with 2.94 gears and small tires, so who knows). However, at 50mph, pressure flatlines. Take the car up to 110mph and still read only 33psi of governor pressure.
I’ve also got the rebuilt carb rejetted and secondary air valve tension set at this point, and can clearly tell the car isn’t downshifting properly at low speeds. So, I check the TV cable adjustment and it has been loosened significantly from where I had it on the original install (I marked the bracket with a sharpie when I found the setting where cable started pulling immediately with throttle open and was fully open at WOT). The cable has been loosened 1/4-3/8” on the bracket. Seems the technician fixed the WOT shift issue by loosening the cable so the throttle valve never fully opens.
I reset the TV cable back where I had it marked before, check that is still the proper setting (no slack at idle, fully open at WOT). Bam, WOT downshifts start working perfectly. However, now it’s back to not upshifting at WOT, and has the same high speed 3-2 downshifting issues.
All of this screams sticky/faulty governor issue to me. Has anyone dealt with this issue on an RH tranny before?
I took the car back and test drove it with the tech on Friday. He’s an argumentative SOB, and wanted to talk about throttle valve pressure, swapping to a lokar kickdown cable, and all kinds of other nonsense. I told him point blank this was not a TV cable adjustment issue, and to stop loosening up the cable to cover up internal issues. After the test drive, where he watched governor pressure on my MicroSquirt laptop, he does agree there’s a governor issue, but says those usually “keep the trans from downshifting” so he doesn’t know for sure. Sounds like BS to this engineer, but this is the kind of guy that can’t be told anything different than what he believes.
Trans shop sent me home and told me not to drive the car while they find a new governor to swap in. I’m frustrated, as this is the second time the car has made the 30 minute trip to diagnose the same issue, and all signs indicate this tech/clown did nothing but swap out a perfectly good valve body (on my dime) and loosen up the TV cable last time I took it in. I also can’t imagine that a 46RH/A518 governor could be that hard to find a replacement for, but I do notice there’s a steel valve replacement for sale at most trans websites that’s supposed to cure a mushroomed factory aluminum valve that can “cause a sticky governor”. Is this a common issue with RH trannys, and if so, should I just tell them to order the aftermarket “fix” valve now?
Thanks guys. Sorry, I tried not to ramble, but I’m upset and it seems I failed.
I’ve been fighting an A518/46RH swap since the summer. Go #1 was an eBay trans I purchased for the swap that lost all forward gears within 3 miles of driving (drove home in reverse, which worked just fine).
Took it to a local trans shop with a really good rep. Got it back after a full rebuild (they never did say what was wrong with it the first time). Got it installed, set the Bouchillon Performance kickdown kit spot on with my factory Mopar Quadrajet throttle linkage, and could not get WOT upshifts. Shifted okay at part throttle, but would go to 6200rpm valve float at WOT without shifting. Shifts immediately upon lifting the throttle some. Would also 3-2 downshift at 90+ mph, going straight to redline.
Drove it back to trans shop and dropped it off. Despite asking them to diagnose the issue with pressure gauges, the “expert” technician replaced the valve body on his gut feel. They call me and tell me everything is fixed, and I go get the car. They also installed a TF-1 shift kit while it was apart due to my complaints about soft shifts.
Driving home, shifts fine at WOT, but softer at part throttle than any shift kit I’ve ever felt. It also doesn’t want to 2-1 downshift, even at low speeds. At this point, with WOT shifts working properly, I move forward with my MicroSquirt install to control OD and Lockup. I’m using a GM oil pressure sensor in the governor port and a MAP sensor to control OD and Lockup. Take it for a test drive to figure out what pressure I want to have the OD and lockup kick in, and notice an issue…
Governor pressure climbs fairly regularly until 32psi at 50mph (seems significantly less than 1psi per mph, but this is a truck trans in a passenger car with 2.94 gears and small tires, so who knows). However, at 50mph, pressure flatlines. Take the car up to 110mph and still read only 33psi of governor pressure.
I’ve also got the rebuilt carb rejetted and secondary air valve tension set at this point, and can clearly tell the car isn’t downshifting properly at low speeds. So, I check the TV cable adjustment and it has been loosened significantly from where I had it on the original install (I marked the bracket with a sharpie when I found the setting where cable started pulling immediately with throttle open and was fully open at WOT). The cable has been loosened 1/4-3/8” on the bracket. Seems the technician fixed the WOT shift issue by loosening the cable so the throttle valve never fully opens.
I reset the TV cable back where I had it marked before, check that is still the proper setting (no slack at idle, fully open at WOT). Bam, WOT downshifts start working perfectly. However, now it’s back to not upshifting at WOT, and has the same high speed 3-2 downshifting issues.
All of this screams sticky/faulty governor issue to me. Has anyone dealt with this issue on an RH tranny before?
I took the car back and test drove it with the tech on Friday. He’s an argumentative SOB, and wanted to talk about throttle valve pressure, swapping to a lokar kickdown cable, and all kinds of other nonsense. I told him point blank this was not a TV cable adjustment issue, and to stop loosening up the cable to cover up internal issues. After the test drive, where he watched governor pressure on my MicroSquirt laptop, he does agree there’s a governor issue, but says those usually “keep the trans from downshifting” so he doesn’t know for sure. Sounds like BS to this engineer, but this is the kind of guy that can’t be told anything different than what he believes.
Trans shop sent me home and told me not to drive the car while they find a new governor to swap in. I’m frustrated, as this is the second time the car has made the 30 minute trip to diagnose the same issue, and all signs indicate this tech/clown did nothing but swap out a perfectly good valve body (on my dime) and loosen up the TV cable last time I took it in. I also can’t imagine that a 46RH/A518 governor could be that hard to find a replacement for, but I do notice there’s a steel valve replacement for sale at most trans websites that’s supposed to cure a mushroomed factory aluminum valve that can “cause a sticky governor”. Is this a common issue with RH trannys, and if so, should I just tell them to order the aftermarket “fix” valve now?
Thanks guys. Sorry, I tried not to ramble, but I’m upset and it seems I failed.
