I-65 around here is a little worse than the other four (I-20 I-59 I-22 I-459). I-65 goes up and down the mountains and valleys. The other four (I-20 I-59 I-22 I-459) stay in the valleys running parallel to the valleys) At work I've been driving a 2009 GMC 1/2 ton 4x4 pick-up. It is equipped with a transmission temp gauge. The engine temp stays at 200degF (once warmed up) at all speeds Around town and on the highway at speeds below 65mph, the trans stays relatively cool. But at higher speeds the trans warms up considerably. That got me to thinking about the Roadmaster. Over heating at interstate speeds could be the trans getting hot and over taxing the cooling Maybe an added trans cooler is in order (?)
We were on your stretch of I-65 a few years back when we stayed in Destin, FL on vacation. That is a long trip down I-65, let me tell you. We had 8 people in a 7 passenger van until we got to Birmingham where we met my son and then his daughter got in their vehicle for the rest of the trip. Fun trip overall, but a long one without stopping for the night. Well, I don't think a trans cooler is ever a bad idea, but I drove a rural mail route for about 19 years. 70 miles of nothing but stop and go driving is about as hard as one can be on a transmission. Never had a cooler on any vehicle I drove and very little problems related to the transmission. Only problems I can recall was on a '86 Pontiac 6000 which had a leaky cooler line which eventually caused the trans to fail. The other one was on a Ford Taurus that I borrowed to drive a couple of days. The guy I borrowed it from had to have the tranny rebuilt after that. Those cars have the weakest transmissions of any that I know of. I can also tell you that transmissions get very warm when driving that way. The car I was driving when I retired a few years back was a 1991 Chevy Caprice wagon. I drove that car for about 5 years on the route with my left leg stretched over the tranny hump to reach the pedals. On warm days that hump got downright hot by the end of the day. YMMV
I have a question for Dynaflow experts. My Electra 1960 dynaflow was slipping heavily in Drive. Reverse and Low work great. I dismantled the whole transmission and replaced everything (rings, seals, gaskets etc..). It now works well. Still some slippage in Drive bt it ends up picking up well. I assumed that was normal for a Dynaslush. I recently drove a friends 60 Invicta who has never touched his Dynaflow in 60 000 miles and in Drive it has very good pick up with practically no slippage. My Low gear and reverse have zero slippage and pickup very sharply. Why do I have pronounced slippage in drive with all seals replaced ? Any know what pieces run in drive and may be worn or improperly adjusted ? Thanks
No I don't have the equipment for checking pressures. Yes I changed the clutch parts. I am trying to find out which component is most linked to Drive.. I remember putting every part together.. Could it be the spacing tolerance between some turbine disk or assembly ? IS the pressure taking easy to do ? I can look into buying a guage.. only problem then are the adapter to hook it up (as I am in europe and everything is metric here !!)...
The most important part of a DynaFlow is the torque converter. ALL the tolerances need to be in spec or else you end up with the problem your having. Today they make needle bearings for some of the thrust washers. Makes it more efficient.
Thanks Tom. I had actually looked into needle bearings but never got the assurance I had found the exact right sizes so I shied away. I tried to make all the bearing fit nice and tight but was dealing with a very worn torque converter so I replaced it with a 61 torque converter which seemed the exact same. Works well but has more upstart slip than other dynaflows I have driven. I would just like to identify the parts that drive that issue to correct it...
One way to do it: I just used the fittings from an aftermarket oil pressure gauge and attached to higher pressure gauge and did the readings one at a time. If the pressures check out then check the orientation of the frictions to the steels in the clutch pack. Torque converter issues would give trouble in all ranges.
Try Lucas Stop Slip. It helped my Dynaflow after a complete fluid change(both the converter and pan). My transmission would lose prime after sitting a week. I added 1 qt. Resolved this issue. Keep in mind my Dyanflow has 35K on it and never removed for work. From my understanding the trans fluids from the era had thicker viscosity than today's. The Lucas thickened the viscosity.
Came across this producer of ATF Type A from Texas - Warren Transmission Fluids. Have not taken the time to call and get specifics regarding "Their Version" of Type A . https://www.warrenoil.com/site/warren-transmission-fluids/ I would be asking them what in particular are they replicating in comparisons to the original formulation of GM ATF Type A .... and .... how is it different from their Multi Purpose Dex/Merc and/or Type F Formulations. Specifically, I would like to know if the anti-slip compound concentrations are different between all of them and if indeed their current Type A would have the same concentration density for flow, anti-slip etc functional spec characteristics when compared/constrasted to the original Type A formulation. Also, how have they improved upon it ? Heck, as long as I am asking questions, would like to know why they bother to make the Type A if as many report the Dex/Merc types III, IV, V etc that are being used as a replacement for the discontinued Type-A fluid product specification meets or exceeds that of the original Type-A specs. Stands to reason if they are bothering to produce the correct formulated Type-A fluid specification, then it must be a world of difference between that and the Dex/Merc formulations. Perhaps for the past 12 years or so the Dex formulations have been creeping ever so far afield from what the original spec Dex III was as a replacement for Type-A that the new Dex formulations are no longer really backward service compatible as much of the current industry literature states as much. Perhaps new formulations endeavor rather to service the new specifications of 6-speed transmissions as well as extremely long high mileage service intervals which perhaps only the internal components of these newer transmissions can accommodate where as in comparison the older iron from 50's and 60's transmission spec's for Type-A just don't have the internal engineered component integrity or engineering to allow for these newer formullatons. I have read where the formulaions have gone so far afield that both heat and slippage is occurring. Well those are of course my ideas and reasoning. Perhaps someone has their own they could share.
Stick with Dex/Merc. Type A is a price leader at Dollar stores which should tell you something. Would you use engine oil with 50-60 year old specs? Dex/Merc in my 55 for 12 years and 90,000 miles: front seal leaking so need to decide if it needed a rebuild or just a seal. Pressure tests were in spec. Pulled the pan and there was about 1/4 teaspoon of identifiable metal particles and just a brown "stain" on the inside. Replaced the seal and some new Dex/Merc and it will outlast me. And it functions as expected.
