M21 transmission questions
Thread Starter
Racer
Joined: Dec 2002
Posts: 306
Likes: 1
From: N. Charleston SC
M21 transmission questions
I have a 69 with a M21.... this is my first 4 speed car... so I have some dumb questions....
Can the gear box lube be checked and changed? … I know there is a drain plug…???
The car has a BB which are notorious for heating problems... but this car stable and doesn’t boil over... but it seems once the car reaches full operating temp a lot of heat is generated off of the transmission as well. Is this normal?
Shifting this baby is a mixed bag.. from 2nd to 3rd is not always true... Finding first sometime can be a challenge... Are these signs of a mis-adjusted/worn shifter or are there some other internal issues starting to surface? Also, I’ve noticed it on several occasions poping out of gear un moderate deceleration…
Thanks
:flag
Can the gear box lube be checked and changed? … I know there is a drain plug…???
The car has a BB which are notorious for heating problems... but this car stable and doesn’t boil over... but it seems once the car reaches full operating temp a lot of heat is generated off of the transmission as well. Is this normal?
Shifting this baby is a mixed bag.. from 2nd to 3rd is not always true... Finding first sometime can be a challenge... Are these signs of a mis-adjusted/worn shifter or are there some other internal issues starting to surface? Also, I’ve noticed it on several occasions poping out of gear un moderate deceleration…
Thanks
:flag
Melting Slicks
Joined: May 2000
Posts: 2,125
Likes: 9
From: Crescent City, CA
Re: M21 transmission questions (Red69)
Guess I'll take first stab at this.
The fluid can and should be changed. Drain fluid and fill to bottom of filler plug on passenger side of the trans.
On heat, there is a collar that will fit around the top and sides of the bellhousing to stop engine heat from going back and there is a trans tunnel insulator that should go between the tunnel and the trans to stop more heat.
Also, check your lower shift boot to make sure it is in good condition.
As far as shifting, I would pull the shifter and clean lube and adjust it. Most, if not all of your shifting problems could be here. If the shifter is worn there are kits that will rebuilt it.
Popping out of gear could be adjustment or a bad syncro.
Hope this helps.
Terry
The fluid can and should be changed. Drain fluid and fill to bottom of filler plug on passenger side of the trans.
On heat, there is a collar that will fit around the top and sides of the bellhousing to stop engine heat from going back and there is a trans tunnel insulator that should go between the tunnel and the trans to stop more heat.
Also, check your lower shift boot to make sure it is in good condition.
As far as shifting, I would pull the shifter and clean lube and adjust it. Most, if not all of your shifting problems could be here. If the shifter is worn there are kits that will rebuilt it.
Popping out of gear could be adjustment or a bad syncro.
Hope this helps.
Terry
Thread Starter
Racer
Joined: Dec 2002
Posts: 306
Likes: 1
From: N. Charleston SC
Re: M21 transmission questions (trw)
Thanks for the info Terry...
Any good tips on actually draining the fluid? ... the plug is actually located above the bottom of the case... I'll probally need a suction pump...?
I've known about the insulation... but I guess I'm really feeling the full affects of not having it in place... I'll have to make insulating my next project.
How can the syncro be checked?
Thanks again
Any good tips on actually draining the fluid? ... the plug is actually located above the bottom of the case... I'll probally need a suction pump...?
I've known about the insulation... but I guess I'm really feeling the full affects of not having it in place... I'll have to make insulating my next project.
How can the syncro be checked?
Thanks again
