I know this is a sensitive subject matter but I need you to keep an open mind and help me through a difficult time I am having. The issue of course is the transmission in my 41 PU, it is a 4 speed automatic and that draws a lot of criticisms and biases from the masses. But as you recall I built this for my wife and she can't drive a stick (I fault her upbringing, personally). But set aside your prejudices and a member out. The problem is not a new one, it has been there since I first drove it. I have been waiting patiently for the only transmission shop in town (hot rod friendly) to clear their lift and work schedule to service it for months! The shop did recommend not driving it until it is fixed which isn't sitting well with Mrs. BB as the nice weather is upon us and she would like to use her truck. Because of this issue the truck has less than 500 miles on it, including engine and transmission. Just to stir the juices I fired it up and drove to get a coffee just now. Hella fun truck to drive other than this: When you leave a light under power the truck launches hard, very hard (not the problem) but at the 1-2 shift, the truck "free wheels" for a second before dropping into gear. Like if you pushed in your clutch (on a proper hot rod) and ran the tach up to 3000 and side-stepped it into second. It will do the same again on the shift from 2-3. If you leave the light like a grandma (or my wife) it doesn't do it, shifts normal, runs fine. It occurs only under moderate or severe power. The transmission is a 46RE (518A) Dodge 4 speed without a locking converter. If you are familiar with the MOPAR nomenclature you know that "R" is for rear wheel drive and "E" is for electronic overdrive. The overdrive is handled by a Mini-Comp shift computer (easier for my wife than toggle switches). It is working the way it was intended, shifting into and out of OD at 60 (where I set the shift point). It has no control of the transmission other than the OD function. The engine is a 330 Desoto, 10:1, 40 over bore, Hemi. It has plenty of power but not more than the transmission can handle. These transmissions were installed behind 5.7 Hemis in Challengers and the like. Point is, they can take what I'm giving it or at least it should. The 46RE is basically a 727 with electronic OD. As is with the 727, they use a TV cable which I adjusted by pinning my carb at WOT, pulling the TV cable taunt at the throttle swivel and tightening the set screw that secures it. Do we all agree that that is the correct method for adjustment? There is no vacuum modulator on a 727 or 46RE transmission. The transmission was a fresh build when I purchased it 5 years ago and the shop where I purchased and had it built it is no longer in business (yeah, there that). While driving it this morning I was able to leave the light, feel the upcoming shift, back off the throttle slightly, wait for the shift and proceed without the aforementioned "freewheeling". once in third a quick smack of the go pedal allowed a downshift into 2nd and nice acceleration and smooth return to 3rd. The next signal I did a granny start (shifted normal) and then accelerated with traffic, at the 2-3 shift it freewheeled again. I was not hard on the pedal, just a 2000-2500 rpm shift. It was a short trip, back home without further incident and I'll put it back in the garage before I hurt it. But I have to know if any of you have experienced anything like this out of a Dodge 727 or later model 46RE? Valve sticking? Something more serious? What the hell is going on with this trans?
Sounds like it needs a whole lot more TV pressure. (Boost pressure) Possibly the ratio for the TV cable on the carburetor is not right. I know you said you set it at wide open throttle, but it may not be right for part throttle. It could also have something going on in the intermediate servo circuit. If it’s a Lokar setup I can almost promise you it’s not right. Just my two cents worth.
@Bandit Billy does that transmission require a lock up converter to function properly? I think most came with a lock up converter. I have a 904 with lock up and my understanding is that unless modified I need to stick with a lockup. Dan
There is a 46RH that doesn’t require electronics and is controlled by a “kick down” or TV cable like a 727 or 904. Dan
Newfangled stuff... needs three pedals... LOL C'mon, man up and teach her how to drive a stick. I remember my dad teaching my sister, she almost got air under the front tires of our '55 Ranch Wagon with the bucking but she caught on.
I have no clue, first venture on these automatics. Intermediate servo? That went right past me. That was my understanding and the directions I received from the guy that built it No. I even called the manufacturer, he said his comp couldn't control that. He used the word "impossible" I am not an expert, I just play one on the internet. I was told that there were lock ups and non lock ups. There is a difference in the bell housing for visual identification. I guess the non lock up, OD trans was a 91-94? model year and the later had lock ups? Hard to pin the info down. The lock up was supposed to get better mileage is waht I heard but the non lock up was preferable for city driving? Again, hard to pin down the intel. Correct, the RH is Rear wheel drive, Hydraulic OD I heard the secrets to a long relationship is never try to teach your wife how to do anything!
If the trans has a 2 pin connector it doesn’t have a lock up converter. They only used these in a few models for a few years before they went computer controlled. I agree with Kevin, I would give it more tv pressure,even if the carb doesn’t open all the way,just to try it. If it’s good,re think you’re cable geometry. Could also be the front band adjustment.
Correct, it has a 2 pin connecter. I failed to mention that. So, to better understand your post, by "more pressure" you are suggesting setting the cable taut at say 3/4 throttle rather than WOT?
Is there slack in the cable when at idle? If so set the tv cable so it is being pulled as soon as the throttle is pressed. Just don’t go to wide open throttle as you will over extended the cable. Drive it at light throttle and see if it still flares between shifts. If it shifts ok the ratio of the carb bracket is wrong.
I will go out and give this a try. "If it shifts ok the ratio of the carb bracket is wrong". Something I had not considered.
Sounds like the line pressure is a little low to me. First thing to check..... Is the trans fluid level right? Yeah, yeah. Sounds basic but, it needs to be verified. What carb are you running, and does the tv cable bracket allow for the correct pull length from idle to full throttle? If the pull length is short, the line pressure could be lower than ideal under throttle. Tv cable setup is crucial to get right. Kits are available for many trans/carb combinations. NOTE: Be careful with what and how you do things. A burnt up transmission is costly....
On the GM overdrives, there is a piston that is engaged inside the pan by the cable. The optimal way to adjust it is to take all of the slack out of the cable by observing its engagement with the piston. There might be something similar on that mopar trans? Dropping the pan is a bitch though. Alternatively someone mentioned the range of the linkage for the cable. I think the GM stuff requires 1 1/4”… If you could nail down what the required swing for your transmission is, it could help with your troubleshooting. This is fresh in my mind because I just went through this on my dad’s OT car with 200 4r… It had similar symptoms to yours.
Update: I checked the fluid level, warm in Park and it was a tad shy so I topped it off for good measure. I checked the TV cable at idle and there was a bit of slack, not enough to measure but the cable stop was not tight against the throttle lever. I loosened the stop and moved it 1/8th of an inch and tightened it back up. Took it for a drive and it no matter how hard I hit it, the "flare" was gone. Tight shifts in all gears and all speeds. Ran it up to about 65, felt the OD engage. All good. Now, explain this. I do not want to burn up the transmission. An 1/8th move on the TV cable, is that enough to do damage? Could this still be an issue with the throttle ratio vs the trans shift lever ratio? Is it enough to be concerned with?
You actually moved it more than 1/8th because you said it wasn’t against the stop. If the shift timing is not too early and you can still get it to kick down at full throttle, you are close. If the carb doesn’t open all the way at full throttle, the geometry is not perfect. A pressure test would verify your adjustment. Your wife may not notice that the carb doesn’t open all the way. The important thing is that pressure rises as soon as you move the throttle.
I think the main concern is with inadequate line pressures and slippage. I’m not an expert, but if it shifts properly up and down and behaves normally under various loads, without slippage, I would start to get comfortable with the idea that you have the problem licked. The only way to know more would be to put a gauge on it and observe line pressures, if that is even possible on those.
There's a good question and I imagine that is what the transmission shop would do. I think at this point I will drive it a bit locally and put some miles on it. It sure ran good just now. Crisp shifts, lots of fun!
When you consider that despite loads of practice and equipment, the individual setting those up in the factory applied probably about 1/10 of the diligence you did making the adjustment. I can imagine there is a certain degree of tolerance for variance in the cable tension.
Let's go with this! So far my only regret was not asking for assistance sooner. This is true, I probably moved it a bit more than the 1/8th but hardly measurable. My wife has never and will never hit WOT, I doubt she knows what it is. The woman has never had a traffic ticket! Doesn't drive that good if you ask me but let's keep that on the down low.
Low line pressure will burn up a trans due to too much heat created from slipping. It can happen fast. Too high is not good either, but for different reasons. Very harsh shifting will be hammering parts together as they engage, and can cause failure. My suggestion would be to back the tv cable off in "poofteenths" until it is just right. It is hard to judge sitting here at a keyboard. One man's hard shift might seem perfectly ok to another. The crucial thing is that it is somewhere in the Goldilocks zone...... no hesitation when shifting, and not stupid harsh when you have your foot up it's arse.
I have three of these cable setups on 727's. I always set them by seat of the pants feel. You being a car person, you know what I'm talking about. If your happy with the shifts and it kick down to passing gear, you are golden. Many miles on all my 727's.
What I have done with transmissions with TV cables, is to measure the arm on the original carb or throttle body that the transmission came with from the factory. Measure from the center of the pivot point or butterfly shaft to where the TV cable attaches. Then duplicate that on my new carb so the cable moves through the same arch.
Late to the thread. Here's the apply chart for 727s. Since the adjustment seems to have resolved the issue, you should be good with grandma driving. If you want to dive into more optimizing and check the other adjustments, I'd do that too. Since it was slipping 1-2 in drive, I'd really pay attention to that front band. If it's way off, either it's been worn or it was not quite right all along. Readjust the TP cable after. That cable is very important to operation, as you have found. If you end up going with another, do a lot of research into which one works well, holds adjustment and is easy and repeatable to install. I've heard of some big names that fail in one or more of these points. Here's a big article about more power than you have, but covers parts. It's where I got the chart, so might as well give them some views. https://automototale.com/news-features/600-lb-ft-chrysler-a727-torqueflite-its-all-in-the-friction/ My long dormant project has a 1992 Dakota engine/trans that is also an OD without lockup. I got it back when the lockup converters didn't have HP aftermarket support so I looked for that specifically. Make sure you ID the YMM of the original trans so you know what parts and adjustments are right. It was a 518 back then, before they changed to the new naming standard.