When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hi there,
This is related to my Jetaway transmission issues but possibly from the engine side of things that’s why I posted here.
Around 620 miles only on this fully rebuilt engine.
Absolutely not a problem with the transmission for the 15 odd years I have owned the car. Been faultless.
In discussions with a supplier of parts for my Jetaway he suggested because of the extensive damage done to the pump by the big washer ( photo attached) I may want to check my crank shaft end float. He has rarely heard of this damage happening but the scoring on the pump raises questions. He also suggested checking the drive plate for bending/warping.
Does this sound feasible?
Does this sound like it could just happen or maybe from rough handling?
What could cause this? Maybe I done something incorrect mating the box to the new engine? Could I please have your ideas/experience regarding this.
Thank you.
Last edited by 5998DownUnder; Nov 17, 2025 at 05:45 AM.
Reason: Photo cut paragraph in two.
The big round thing is the pump rotor for the transmission pump.
How did you set the converter spacing when installing the transmission to the engine? If the converter is smashed into the transmission then it'll tear up the pump. The general process is to push the converter all the way back making very certain that all the parts of the converter are correctly engaged, install the trans onto the engine, ensure there is a gap between the flexplate (what you called a drive plate), then use washers to take up all EXCEPT about 1/8" gap. You want the converter to be pulled forward just a little bit. The converter will expand under pressure and push backwards, so it needs a little room to breathe.
The crank has endplay - it has to be able to move forward and backward or else it will tear apart the thrust bearing inside the engine. But that endplay is supposed to be around 0.010" - far less than the gap we just made for the converter. A crank that can move enough to cause this kind of damage would also destroy the engine quite quickly.
Don't assume that the converter spacing is OK just because a similar engine was used previously. It really does need to be re-checked any time the transmission, converter, flexplate, crank or block are replaced.
Installing a converter without enough space between it and the flexplate is very common.
The big round thing is the pump rotor for the transmission pump.
How did you set the converter spacing when installing the transmission to the engine? If the converter is smashed into the transmission then it'll tear up the pump. The general process is to push the converter all the way back making very certain that all the parts of the converter are correctly engaged, install the trans onto the engine, ensure there is a gap between the flexplate (what you called a drive plate), then use washers to take up all EXCEPT about 1/8" gap. You want the converter to be pulled forward just a little bit. The converter will expand under pressure and push backwards, so it needs a little room to breathe.
What you have described here is the procedure for a 1965 & up Turbo-Hydramatic. Not a 1959 Dual-Coupling. see the illustration below.
That being said,
The crank has endplay - it has to be able to move forward and backward or else it will tear apart the thrust bearing inside the engine. But that endplay is supposed to be around 0.010" - far less than the gap we just made for the converter. A crank that can move enough to cause this kind of damage would also destroy the engine quite quickly.
Don't assume that the converter spacing is OK just because a similar engine was used previously. It really does need to be re-checked any time the transmission, converter, flexplate, crank or block are replaced.
Installing a converter without enough space between it and the flexplate is very common.
