Thread: Torque converter problems

stall test.

then replace everything that gets broken.

you might find its the flex plate giving up.

A common cause of flex plate failure is forgetting to install both dowels into the bellhousing face of the replacement engine when doing a swap. The resultant misalignment will kill a flex plate quite quickly.

Originally Posted by steve_35

It also has a lot of drag when taking off from a standing star

Make sure the handbrake isn't binding. Mine drags a bit first thing in the morning but that's due to oil contaminated linings. The handbrake can also make strange noises but not normally what you've described.

Originally Posted by steve_35

So i have a noise coming from under my Discover It a V8 auto 93 model

When its cold it has a horrible rattling noise coming from the transmission that goes away once its cruising
It sounds like putting a metal ball inside a big can and shaking the hell out of it
It also has a lot of drag when taking off from a standing star

It seems to get a lot better once its warmed up

Im thinking torque converter anyone got any advise on checking it
I just don't want to buy a new one and it be the transmission

Take off the inspection plate and check that the Torque Converter bolts are there and tight, check for any cracks in the plate, Regards Frank.

Originally Posted by bee utey

A common cause of flex plate failure is forgetting to install both dowels into the bellhousing face of the replacement engine when doing a swap. The resultant misalignment will kill a flex plate quite quickly.

Bee utey this is the second time I have heard this statement in 2 weeks .
can you elnlighten me as to what the difference would be with the alignment?
Wont the gearbox bellhousing to block bolts self align the bellhousing to the block when bolted up?
The reason I ask is After replacing my engine in my Rangie (89) last year sept I found that in feb this year the flex plate cracked and I had to remove the transmission (auto) and replace the cracked flex plate . I had a low kilometer autobox (from a 95 disco 70k) one sitting ready to bolt up so decided now was the time. Problem was I couldn't get a flex plate in aus new,
So had one made up by a laser cutter place that was 3.2mm thick instead of the original that was 2.7mm thick. Comparing holes etc it was perfect
Now I am sure that all the engine dowels were there when I fitted up the new box but at 2000 rpm I have a vibration coming from the steering and through the floor. I can feel it from the acc pedal as well. I did replace the gearbox mounts with new. I did not have this vibration before I replaced the box and I was asking a auto trans re-builder re my vibration the other day and he said exactly what u said about the dowels missing could cause the flex plate to crack. So far I have done about 5k with the new box and no problems or oil leaks but the vibration irritates me. At higher revs it is not there and is only there under acceleration, coasting is smooth.
I thought maybe the exhaust was touching but its not. I was also wondering if the new rubber mounts were to hard.
I think I may recheck and see if both dowels are there when I next get a chance but would be interested in your's or anyone else's views on about the dowels.

Steve your noises sound exactly like my flex plate going but mine got worse when it got warm. In the end I had one bolt holding it all on to the torque conv. As franks says take off the bottom cover plate and put a big screwdriver in and try and lever the flex plate and you should hear it creak or see the cracks around the bolts.

Brad

Originally Posted by Bradtot

Bee utey this is the second time I have heard this statement in 2 weeks .
can you elnlighten me as to what the difference would be with the alignment?
Wont the gearbox bellhousing to block bolts self align the bellhousing to the block when bolted up?
The reason I ask is After replacing my engine in my Rangie (89) last year sept I found that in feb this year the flex plate cracked and I had to remove the transmission (auto) and replace the cracked flex plate . I had a low kilometer autobox (from a 95 disco 70k) one sitting ready to bolt up so decided now was the time. Problem was I couldnt get a flex plate in aus new,
So had one made up by a laser cutter place that was 3.2mm thick instead of the original that was 2.7mm thick. Comparing holes etc it was perfect
Now I am sure that all the engine dowels were there when I fitted up the new box but at 2000 rpm I have a vibration coming from the steering and through the floor. I can feel it from the acc pedal as well. I did replace the gearbox mounts with new. I did not have this vibration before I replaced the box and I was asking a auto trans rebuilder re my vibration the other day and he said exactly what u said about the dowels missing could cause the flex plate to crack. So far I have done about 5k with the new box and no problems or oil leaks but the vibration irritates me. At higher revs it is not there and is only there under acceleration, coasting is smooth.
I thought maybe the exhuast was touching but its not. I was also wondering if the new rubber mounts were to hard.
I think I may recheck and see if both dowels are there when I next get a chance but would be interested in your's or anyone elses views on about the dowels.

Brad

OK I have been there, both myself and with customers cars. The dowels are pretty precise and closely align the centre axis of the engine and auto box. The bell housing bolt holes are a bit sloppy and so allow slightly off centre bolting of the gearbox. I have observed problems with dirt/bits of wire in the gap between the two housings too. Flex plates really don't like flexing at all, a few thou off line may fatigue the centre right out of it.

Your vibration may be unrelated to the offline, it may simply be a faulty converter. This is the heaviest rotating mass in the driveline after the crank. I would try finding another converter before any further dismantling.

This is kinda related as a suspect ...

If the back of the block + all mating surfaces / was not 100% clean of all dirt & sand ... This also will cause problems

Mike

I have a P38a sent here that has had 4 flexplates, and the engine has had a vibe since new. The only way to rectify this one is to replace with a short engine. It has only covered 120k.
First 3 flexplates done under warranty. No mention of a cause of the failures apparently at the time. Now it is out of warranty well and truly, the owner has to decide to fix it and pay $$$, or walk away.


I'd be thinking about checking that vibration out or another flexplate will be needed.

JC