727 torqueflite intermittent loss of power
 

Hello,

I would need some help please on an annoying intermittent issue with my 727.
The vehicle is a heavy 1988 Dodge B350 (TBI), 110k miles.

I have sometimes a complete loss of power on the first gear and reverse. It lasts a few seconds then it goes giving me a normal acceleration..
When it occurs, the van cannot move anymore, rpm blocked at 2000. It doesn't slip however.
It comes with a scary rattling noise. It disappears the moment i put the gear in Park or Neutral.

It seems to be located around the TC, the flexplate.

I did an tranny oil and filter change. All seems clean. The magnet has a bit of metal dust but no big chunks.

I could drive 1k miles without any issue at all.

Could it be a broken flexplate? Some loose TC bolts?
If so How come as it is intermittent?
My next step will be to remove the 727 cover plate.

I am on my own because of the type of this vehicle, a class B camper van, very tall.
It doesn't fit most repair shops.
Plus I want to learn, to fix it by myself.
It is my daily, my home on wheel.

Thanks for your suggestions.

My first thought is it's low on fluid or theres a problem with the filter....

Sounds to as if something in the Valve Body of the trans is hanging up. Probably need the trans taken apart and freshened up along with a good Valve body cleaning and inspection.
Best of luck.... Mopar on !!

Thanks for your answer guys.

All is fine as I've just done the oil and filter change.

It looks like an fluid issue you are right Iowan, like a part of the tranny becoming suddenly dry (TC?).
At it is intermittent, it couldn't be completely or partially clooged, logically.

I use to let the tranny warming up a few seconds putting the gear in Neutral.
It seems to help.

I hope my 727 isn't fried because it is intermittent, running strong and smoothly 95% of the time.
I have done several thousands miles till the problem appears and it doesn't getting worse...

This tranny has a nice cooler, was well maintained, never beaten and this is a 727 after all.

Saric -

Sounds more like you need a band job.
Unless you're comfy taring down a 727, I'd bring it to a tranny shop.

Archer

I went to two other tranny shops and finally got the same diag, a worn torque converter.
The rattling noise comes from its bearings..
They were just surprised that the noise and power loss is intermittent.

So the tranny is stilll good but full of aluminium flakes, dust coming from the TC disaggregating itself; with times, it will surely destroy the whole tranny.

I will dismount my 727 then change the TC myself.
It doesn't seem difficult to do but I will appreciate any good tip.

My concern is to find the right way to clean the transmission, removing any oil, metal dust and flakes.

Will it works with several oil and filter changes once the 727 will be rebolt to my 318?

Is there a better way?

Thanks in advance.

You will need to disassemble and clean the unit completely and replace everything that is worn, and flush all the lines and add an inline filter.
But if your just going to throw a convertor at it and hope for the best? We wish you good luck... I know with my luck, the trans would take a dump in 100 miles...