85 Bronco II with AL4D problems

[bonedoc]

Hey guys...just looking for some insight. Have an "85 Bronco II with about 25,000 on Jasper motor. The AL4D trams was completely overhauled just a hair under 20,000 miles ago after it blew the trans pump seal and pumped all the fluid out at about 70 mph. Well it blew again, yesterday while on the highway. Anybody have any suggestions as to why it blew or what can be done to prevent it from happening again. I'm planning/collecting parts to duraspark it and swap carb. Would love to swap transmissions or even better a 4.0L motor and trans swap but that isn't in the cards right now do to personal reasons plus it is my only vehicle at the moment.

Thanks

 

[jg09]

did you ever check your tranny fluid since it was rebuilt? did it ever shift funny/hesitantly before it blew again? what were the driving conditions when it happened (uphill? hot?)

 

[trail B2]

If there is any kind of resistance in the cooling system for the tranny the resistance in the line puts pressure on the seal and blows it out.If you had the tranny built 20,000 miles ago look for one of those inline filters in the cooling circuit if it's restricted just a little it will roll the seal out and it pops back after it runs out of fluid or pushes the whole seal out.When it does the later you have to pull it for repair.This isn't like a fuel filter it only takes a little resistance.

 

[bonedoc]

The fluid level was good. Yes it has had hesitation problems..always seemed like a timing issue...which is why I was planning on a duraspark and carb swap. I was running on the highway, here in northeast Pa that is up and downhill. Was coming up a hill when it blew. It didn't seem to be slipping at all. Was running 55 to 60 mph. They had checked the tranny cooler when they did the last rebuild, an almost $2,000.00 job. So they are going to check it out and make good on some portion of it but still want to prevent it from happening again.

Thanks