AP2 trany secondary shaft & gears in a AP1
Thread Starter
Registered User
Joined: Sep 2003
Posts: 212
Likes: 0
From: OMAHA
AP2 trany secondary shaft & gears in a AP1
i just broke 4th gear this weekend at mid america motorplex. it was a AP2 trany which has the "better" secondary shaft and gear for lower gear ratio. i own also AP1 trany and was wondering if anybody has swapped out the secondary shaft and secondary gear set from one to another. i know the rear tailshaft housing/case is the same, but i do not know if the splines on the countershaft are the same or not for this to work, 
note: i have seen aftermarket companys offer a secondary gear and not the shaft before, this is what makes me think the splines might be different?
note: i have seen aftermarket companys offer a secondary gear and not the shaft before, this is what makes me think the splines might be different?
Registered User
Joined: Jun 2010
Posts: 285
Likes: 0
From: Michigan
In for any information on this. I was just thinking about this a couple weeks ago...looks like if I want to use my dyno reclass for NASA TTC, I will have to use an AP1 transmission.
I'm not very familiar with these transmissions, but is it possible to swap your AP1 4th gear (and 5th and 6th) into your AP2 transmission? If so, that would accomplish the same goal.
I'm not very familiar with these transmissions, but is it possible to swap your AP1 4th gear (and 5th and 6th) into your AP2 transmission? If so, that would accomplish the same goal.
Joined: Apr 2008
Posts: 1,840
Likes: 21
From: Salt Lake City, UT
Nice! I have heard of people putting in the AP2 secondary gear reduction in AP1 to get a better 5th and 6th gear ratio. 1st to 4th gear will be the same as before. I think this is a good mod for AP2 owners.
Former Moderator
Joined: Jul 2005
Posts: 4,634
Likes: 28
From: West Virginia
This is a sweet mod. Putting the AP2 secondary gear in an AP1 transmission will lower all 6 gears. This is a worthy mod for someone putting an AP2 motor in an AP1 chassis. Don't forget to swap the light AP1 flywheel onto the new AP2 motor though.
[edit: removed statement about AP2 motor and AP1 transmission being bad gearing match]
[edit: removed statement about AP2 motor and AP1 transmission being bad gearing match]
Thread Starter
Registered User
Joined: Sep 2003
Posts: 212
Likes: 0
From: OMAHA
its in and running and moving now. it works 
note: i feel sorry for the guys that have to do the trany on the ground with out a hoist, because that clutch release arm is a P.I.T.A!!!!
note#2: since you have to press the bearing onto the clusther shaft, i just used the middle chassis boltthat is 14mmx1.5 as the bolt to use with a bunch of shims, hope this helps
note: i feel sorry for the guys that have to do the trany on the ground with out a hoist, because that clutch release arm is a P.I.T.A!!!!
note#2: since you have to press the bearing onto the clusther shaft, i just used the middle chassis boltthat is 14mmx1.5 as the bolt to use with a bunch of shims, hope this helps
Trending Topics
Joined: Oct 2008
Posts: 4,806
Likes: 14
From: St.Petersburg/Tampa, FL
This is a sweet mod. Putting the AP2 secondary gear in an AP1 transmission will lower all 6 gears. This is a worthy mod for someone putting an AP2 motor in an AP1 chassis because the AP2 motor + AP1 transmission is the worst possible combo for gearing. Don't forget to swap the light AP1 flywheel onto the new AP2 motor though.