AMGBA website home page or AMGBA Photo Gallery or AMGBA Club Blog
Subscribe in a reader


Join or renew today and receive a free t-shirt or tech CD, see details in the join the club section at www.mgclub.org!

Author Topic: Overdrive Installation  (Read 208 times)

0 Members and 1 Guest are viewing this topic.

december2021

  • An AMGBA Club Member
  • ***
  • Posts: 25
Overdrive Installation
« on: November 21, 2021, 07:07:51 PM »
I picked up a used overdrive unit to install in my 1977 MGB. The gears look excellent in the gearbox and the gearbox turns smooth through the gear patterns when I turn the input shaft. I will change the front and rear main seals plus O/D filter. There is a cover plate missing from the O/D unit and what I think is from MOSS parts catalog the coil assembly. Iím not sure if its stuck up in there from the pictures or all missing? If stuck how would you remove it? See pictures

Please fill me in on what you know. I can make the cover plate out of aluminum from a new gasket used as a pattern. Throw in any other suggestions.

Oh, is this a drop in replacement for my old 4 spd?

Regards
Fred Mauro
Bethlehem, Pennsylvania

JohnTwist

  • AMGBA Club Tech Staff
  • ****
  • Posts: 132
    • University Motors
Re: Overdrive Installation
« Reply #1 on: November 22, 2021, 10:57:52 AM »
Youíll want to purchase a new solenoid assembly.  Itís available from Moss #80 on page 41 Ė 466-375.  Remove the remainder of the solenoid assembly with a pair of needle nose or duck bill pliers.  The piece youíre trying to remove looks like a top hat and youíre looking at the bottom of it. 

Iíd clean out the overdrive and replace the O rings right now while itís out. 
Oh Ė if itís a top fill gearbox, then itís probably set up for 1280 turns per mile on the speedo cable; if itís a side fill gearbox, then itís probably set up for 1000 turns per mile.  You want the later, 1000 tpm for your car, or the speedo will read 25% fast.
Except for the wiring, itís a straight drop in.  Make CERTAIN you check the 4th gear switch about 20 times.  After installation itís the least accessible electrical component in the vehicle.  Itís at the right front of the top of the remote control assembly.

Hope this helps.

SAFETY FAST!
John H Twist
University Motors Online
Cell:  616 307 6737
www.universitymotorsltd.com
SAFETY FAST!
John H Twist
University Motors Online
100 East Beltline Avenue SE
Grand Rapids, MI  49506

616-307-6737
johntwist@universitymotorsltd.com
www.universitymotorsltd.com

If you have found my technical advice helpful, please consider making a contribution to help defray my online expenses.  Go to my website and click the PayPal button: www.universitymotorsltd.com.


 

†† AMGBA website home page or AMGBA Photo Gallery or AMGBA Club Blog