I'll try and be brief. Looking at a 58 Buick Special for sale. Has a 364 and dynaflow. Seller said last time he drove it (3 years ago) it ran fine down the road fine, once it "warmed up" the trans would start to smoke after coming to a stop...sounds like a faulty torque converter right? Unit not disengaging and hence burning up the rings in the ******? Done a little research and from what I can determine the trans/converter may be a bit different from other years. Would like to repair the trans myself or swap out the drive line for an open unit, any opinions on how you would proceed would be appreciated. I have a later model Pontiac TH350 (would that bolt up to the nailhead?) and a couple different rear ends (60 El Camino/68 Impala) that might measure up. It's a nice solid sedan that I would enjoy driving, just don't want to throw a "lot" of extra money at. Thanks! Alex
Does the car slip when it gets hot? If so it could be the converter. Need to try R and Lo when the trans starts to smoke and let us know if it slips in all driving ranges. Could the smoke be that the trans leaks all over the exhaust system? Dynaflows are relatively easy to rebuild, and parts are available. A TH350 would only bolt up to the 364 with an adapter plate. The adapters are not cheap! Neither is converting the closed driveline to open driveline. I have a 58 Roadmaster with Flightpitch trans. It runs fine, but does leak a little. If it goes out, I simply rebuild it, even though parts are almost impossible to get. But if I was to change the transmission out to a more modern transmission, I would change out to a Ford C4 box, and use the bell housing from the Dynaflow, along with the tailhousing. The tailshaft of the C4 may have to be modified to allow the Dynaflow u-joint to fit and be retained. Another approach I am toying with is to find a mid 50's Nash with torque tube driveline. It would have the old dual range hydramatic, but would still be a closed driveline. It would be possible to use the Olds or Cad bell housings from 1954 back and then have an adapter plate made to go to the 364. Another common swap is to put a switch pitch 400 from a 65-66 Buick behind the 364. This swap is minimal cost and requires a simple bushing and newer flexplate. I believe the later starter must be used too. Check the Buick websites for swap details. However the driveline will need to be changed out.
Thanks for the input! Heading down to look it over today. Fluid from the ****** splashing onto the exhaust has some merit. Owner didn't say the ****** slipped just that it would smoke after it was warmed up and while in gear at a stop. Keeping my fingers crossed. Were all the dynas "Flightpitch" for that year? Is there a code to indicate the type on the trans or cowl tag? Thanks again! Alex
No, Flightpitch trans was standard on Roadmasters and Limiteds, optional on the other series cars. Flightpitch has a square pan and quadrant is PRNDG. Dynaflow has a rectangular pan and quadrant is PNDLR If you have Dynaflow you might want to have mechanic check the vent tube for obstructions. You will find it toward the back of the transmission and on top. Being plugged up may cause fluid to flow out of dipstick tube and drip on exhaust.
You're boned either way you go if the trans does go - the torque tube locates the rearend in these cars, so to go to open drive you have to re-engineer the rear suspension in some way - add trailing arms at the least - to keep the rearend properly located. There is a TH400 that bolts up to the 364 - used in 64-66 Buicks with nailhead and 66-69 or so Jeep Wagoneers (will need a short tail housing for 2WD) as well as some more exotic cars. GM sold the trans with the nailhead case for a few years as sort of a universal trans, and some of the smaller carmakers used them. Further, you can keep the stock rear housing (I believe, I know this works on 59-60) using a 61-62 center section. Then you really only would need to add some kind of trailing arms, as opposed to figuring out another rearend.
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