Automatic box problem - any ideas?

[rhysd2]

Heya guys

got myself a 70's mustang and having a bit of an odd problem with the automatic box on it

when it changes from first to second it crunches. But not all the time. If I accelerate at a regular pace it doesnt crunch. If I accelerate at a quick pace and it changes up then it crunches(the same sort of sound a manual car makes when you change gears without depressing the clutch)

I've spoken to a few auto gear box places today and every single one has said "oooh never heard of an auto box crunching like that before..... bring it in and we'll see"

Unfortunatly they all only seem to open during the week so its going to be tricky. Figured it cant ask to ask here first. Anyone have an idea? box was rebuilt a few months back so cant imagine it'd be broken...

Cheers

Rhys

[Tony427]

I've had a number of cars with auto boxes and never experienced the crunch...........

Who rebuilt the box?

Take it back to them and get them to fix it as it sounds like its their problem.

Cheers,

Tony

[Slinky]

Speak to Mr Frost Redvictor .. he may be able to advise... just maybe..

[rhysd2]

wish I could take it back. the garage has since gone bankrupt. I'll message that chap thanks for the input

[lenientism]

How long have you been identifying this crunch? Perhaps it was character of auto from era 70's

[plasticpig]

From you description I think you may have problems with the torque converter rather than the auto box.

[lenientism]

rhysd2 said:

Heya guys

when it changes from first to second it crunches. But not all the time. If I accelerate at a regular pace it doesnt crunch. If I accelerate at a quick pace and it changes up then it crunches(the same sort of sound a manual car makes when you change gears without depressing the clutch)

This looks like late of fluid circulation in the transmission system. Regular acceleration will give more chance to the fluid circulated properly, while quick acceleration will need quicker fluid circulation.

For vehicles whose mileage over 150k, such problem would be more acceptable. But if the auto box has only months ago rebuilt perhaps it has some components missing.

Perhaps to flushing the fluid more often will help a bit, at least the transmission runs on cleaner fluid relatively free from dirty of residue that may cause circulation of the fluid retarded.