5 speed repair

Tech tips and how to's

Moderators: notoptoy, S Allen, Solex68

Post Reply
browne
Roadster Newby
Posts: 23
Joined: Fri Dec 06, 2002 8:57 am
Location: San Pedro , Calif

5 speed repair

Post by browne »

please explain th 5th gear repair to me. what am i looking for.? where is it
? what do i do when i find it?
User avatar
S Allen
Site Admin
Posts: 4521
Joined: Thu Dec 05, 2002 4:57 pm
Location: Knoxville, IA(Lake Redrock)Emory, TX
Model: 1500/1600
Year: Low Windshield-64-67.5
Contact:

RE:5th Gear Neutral

Post by S Allen »

You must be talking about the 5th gear neutral syndrome. I am not sure of the visual differences or the serial #'s between an early or later tranny. The earlier transmission has a *single* big nut at the back that can loosen up thus causing 5th gear neutral. I would say we are speaking of 67.5 five speeds as early and possibly 68 and above being the later trannys. I do not know this to be a fact though. On later 5 speeds there are *two* big nuts at the back that are tightened against each other to around 220ft/lbs. It is hard to belive this double nut would loosen up but I am sure you can still have the problem as the main shaft 5th gear itself was poorly designed. I believe all of the 5th gears were press fit together early and late. All of the other gears are splined. What can happen? The torque being put into the outer portion of the gear is too great for the press fit and this outer part of the gear does not transmit any power to the inner part of the gear. This all equals no power transmitting to the main shaft. If this happens on the early tranny it can wreak alot of havoc. Excessive gear noise and wear to mention a few problems. I have heard it is not as big of a deal on the later trannys but can still lead to 5th gear neutral. Several of the vendors sell a 5th gear that is either splined or welded which eliminates the poor press fit design of the original 5th gear. Needless to say you have to tear the tranny down to visually see the 5th gear and nut or nuts.

Steve
66 Stroker-Going Orange
67 SRL311-00279-resto project
Stock '72 240Z-Blue
2002 Ford F250 7.3 Diesel 2WD Hauler
2008 Toyota FJ Cruiser
2009 Smart ForTwo Passion Coupe
2013 Fiat 500 Abarth
User avatar
S Allen
Site Admin
Posts: 4521
Joined: Thu Dec 05, 2002 4:57 pm
Location: Knoxville, IA(Lake Redrock)Emory, TX
Model: 1500/1600
Year: Low Windshield-64-67.5
Contact:

RE:More 5th Gear Neutral

Post by S Allen »

Robert,

Another fix for the 5th gear neutral problem is to drill the nut and shaft through so you can fit a split pin in to keep the nut or nuts from backing out. Got that one out of Phil Brook's Fair Lady book.

Steve
66 Stroker-Going Orange
67 SRL311-00279-resto project
Stock '72 240Z-Blue
2002 Ford F250 7.3 Diesel 2WD Hauler
2008 Toyota FJ Cruiser
2009 Smart ForTwo Passion Coupe
2013 Fiat 500 Abarth
Post Reply