Thread: Transmission removal, flexplate repair

Well after nearly 4 months tackling this task, i'm pleased to say it's mission accomplished. And what a mission it was.

Thanks to the advice of fellow AULRO members in Tips, advice & recommended places to get the torque converter reconditioned. I look back now, if i didn't put this thread up, i reckon i would've been somewhat lost.

So, the work that was done:

- new flex plate
- replaced the TC pump seal
- second hand ring gear replaced & balanced
- second hand sprigot aligner
- replaced all 8 bell housing bolts
- new catalytic converter & y pipe
- new handbrake shoes
- TC machined and reconditioned
- transmission filter replaced


I had a few mishaps in the process of re- installing the Tranny as a bolt came loose from the transmission support plate and the tranny tipped off landed side on onto the garage floor with a thud!! Lifting it back up was almost near impossible underneath the vehicle with the limited room. Took me about 7 goes using a smaller jack and blocks of wood slowly propping the tranny high enough to slide the support plate below it again. Then slowly millimetres by millimetres the transmission worked its way onto the engine, making sure the dowles aligned and seated correctly. All 8 bolts tightned up with relative ease to the correct torque.

This morning when i turned the key and heard that V8 instantly come back to life, what a relief that was. I did notice that the engine was idling rather fast to which a quick clean of the MAF sensor quickly rectified that issue.

With the new exhaust and cat converter, the engine has more torque, and slightly more power. The flat spot is no longer there, and super smoothness has returned to the torque converter.

All in all, i'm wrapped with it so far, and wiil take it for a longer test drive on Thursday.

Sorry for not posting up too many pictures, as i was so focused in getting this job completed.

So thanks again for everyones help and hope to return the favour if anyone else is game enough to tackle this job.

Well done, a great result.

Mate

Well done, persistence pays off, lets hope the beastie rewards you

Steve

Originally Posted by SteveFarmer

Mate

Well done, persistence pays off, lets hope the beastie rewards you

Steve

Already had an invite to drive someone up to the snow. In style off course!!!

Well done Andy,
So was there anything in particular that caused the failure or just wear & tear? What were the symptoms? It might help someone else diagnose if similar thing happens!

Originally Posted by FANTOM P38

Well done Andy,
So was there anything in particular that caused the failure or just wear & tear? What were the symptoms? It might help someone else diagnose if similar thing happens!

It seems that a chain of events occurred that caused the failure. It all started with the flexplate as metal fatigue was working its way around the crank bolts. Eventually with the excess movement of the Brocken flexplate causing torque converter to move slightly forward causing the flexplate to TC bolts to catch onto the timing spikes in front of the ring gear from that movement causing a small section of that spike to tear away and eventually strike the crank position sensor. With the CPS now bent, the ignition system was no longer getting a stable timing signal causing the engine to stop. A replacement CPS wouldn't of helped as the Brocken metal piece was still in there, which would've damaged the new CPS again.

When the tranny was pulled back, the Brocken section of the timing spikes was found mangled and squashed underneath the TC.

The flexplate did suffer from a bit of corrosion too from water ingress from those deep river crossings.

So yes in a way you could say general wear and tear, and a bit of constant strain from pulling heavy camper trailers, heavy duty 4 wheel driving on steep climbs and steep downhill in low range using engine braking which all put a fair amount of pressure onto the flexplate. Therefor a lesson there would be to take it easy and not over stress the auto in any car really.

Another thing that come to mind that over the years as the Rover V8 increase in cubes and power without any real major changes on the ZF autos, maybe a natural progression of excess stress on the tranny as the years of extra development went on in the Range Rover world, and the transmission may have been over looked. In other words, if it ain't broke, don't fix approach, which I dare say was common in earlier testings with a cash strapped Land Rover made do with what they had. Correct me if I'm wrong though!

Originally Posted by 81stubee

I would never use a secondhand flex plate, as buying a new one should be easy. Ring gear might be hard to get.

Given A$ list price for a V8 flex plate is over $800- and even second hand ones command $2-300 I got lucky and found one for $25-.

And landed new from the UK (Ashcrofts) are <$100-.

Also as I fitted a 4HP24 to a D2 and HD TC, the stack height of all the flex plate components (spacers etc) is slightly different to a 4HP22, about 1.5mm, enough to make a difference to the TC engagement in the pump. Found while checking and surface grinding the spacer that the spacer wasn't flat and the big steel boss mounting surface wasn't true either. Ended up milling 50thou off the boss and making a new spacer.

And yes, flywheel is manual, flexplate is auto, ringgear is fitted to both to engage the starter

Originally Posted by clubagreenie

Given A$ list price for a V8 flex plate is over $800- and even second hand ones command $2-300 I got lucky and found one for $25-.

And landed new from the UK (Ashcrofts) are <$100-.

Also as I fitted a 4HP24 to a D2 and HD TC, the stack height of all the flex plate components (spacers etc) is slightly different to a 4HP22, about 1.5mm, enough to make a difference to the TC engagement in the pump. Found while checking and surface grinding the spacer that the spacer wasn't flat and the big steel boss mounting surface wasn't true either. Ended up milling 50thou off the boss and making a new spacer.

And yes, flywheel is manual, flexplate is auto, ringgear is fitted to both to engage the starter

I think you might be refering to the Ring Gear at $800. Flexplate was only $57 from British car components.

I was quoted $1300 in total to have a brand new ring gear imported from the UK. My second hand one was around $90, but needed balancing.