No gears!
 

:mad: My 420sel just lost all forward and reverse gears HELP! Cars a 1991 and the transmission was rebuilt 2 years ago and has been working perfectly till the other day .I reversed out of a parking space switched into drive and nothing , reselected reverse nothing no gears . Checked the linkage all fine ,oil level fine ,dropped the oil pan everthing looked clean and the filter was not blocked and gear change plunger was moving in and out of the valve body . Moving on decided main pump might be kaput so pulled driver side oil cooler line and started engine after a brief spurt no oil flow so dropped the transmission .Removed torque convertor lokked fine full of clean oil .Removed main oil pump , drive tabs were in place and pump looked great Removed valve body everything looks clean no signs of broken bits or dirt ! Please anyone any ideas what could be causing the lack drive .There was no wierd noise no warning just suddenly no gears . Help!!!

transmission modulator? solenoid? not sure

That sounds like the weirdest thing ever.

So you had reverse - then nothing.

I guess it isn't this but you didn't specifically mention it - so I'll ask => was the torque converter fitted to the fly wheel correctly?

Can you post up some pictures of the end of the torque converter - and some pictures of the front pump?

What does the condition of the oil filter look like? (Picture?) Was the oil clean - is there something stuck in the filter preventing flow?

Same thing happened to my SD. Turned out to be the front pump seals even though they looked good.

Have you checked the drive line? .........perhaps...just perhaps, the drive shaft or axles have sheared or whatever.

Never experienced a sudden loss of motion without some noise.


.BTW...Don't get under it to check with engine running in drive though...

I had a Dodge do that once.Turn out a metal part inside tranny pan had broke,it shifted the gears.A $1.00 part,I made one with spring steel.

update
 

Hi Guys ,thanks for the replies here goes .
The driveshaft and flex plate are fine.
Torque converter looks perfect and the oil was clean.
Tranny filter was clear and very clean.
Modulator looked okay nothing broken.

So maybe those seals behind the front pump /(white teflon rings?) or something in the valve body (pressure relief valve?)
Tomorrow I will seperate the valve body and check out the relief valve .
To be continued :-

steve

magical returning gears!
 

:)Well after much head scratching still nothing found to explain the lack of gears .Stripped the whole valve body cleaned everything very carefully reassembled and refitted transmission . Voila I have gears ,guess it was a stuck valve !Still makes me worried everytime I go from reverse to forward though .