Manual Transmission Conversion

Drivetrain discussion including Transmission, Differential, Driveshaft, and related items.
kras007
Posts: 27
Joined: Sun Feb 26, 2017 6:54 am

Re: Manual Transmission Conversion

Post by kras007 » Mon Mar 06, 2017 3:01 am

The car has a 3.45 gear ratio rear axle that was installed prior to the manual trans conversion. I'll monitor and post the rpms in 6th at highway cruising. Pickup and acceleration feel greats shifting through the gears. Car can be driven real easy and feels comfortable or it can be romped on. Feels great either way. LS7 clutch makes it really smooth

Jeff M
Posts: 10
Joined: Wed Oct 12, 2016 8:06 pm

Re: Manual Transmission Conversion

Post by Jeff M » Sun Mar 12, 2017 2:11 am

Could the rewiring be avoided by just reprogramming the TCM?

kras007
Posts: 27
Joined: Sun Feb 26, 2017 6:54 am

Re: Manual Transmission Conversion

Post by kras007 » Mon Mar 13, 2017 3:10 pm

Unfortunately no. The TCM is part of the automatic transmission. Once the automatic transmission is removed the ECM can not start the engine because the ECM needs to verify the vehicle is in park which was communicated to the ECM by the TCM. The ECM is now programmed to not look for the Park signal from the TCM, instead it relies on the BCM to start. The BCM allows the ECM to start the engine when it sees the clutch pedal depressed. ECM and BCM need the circuits that read the manual transmission sensors and safety devices. Some are in the factory harness, some are missing, and a few just need to be moved to different positions in the connectors of the body harness. It took a lot of work to figure it out but once it's done you would never know the harness was modified.

Jeff M
Posts: 10
Joined: Wed Oct 12, 2016 8:06 pm

Re: Manual Transmission Conversion

Post by Jeff M » Tue Mar 14, 2017 2:54 pm

Wow! sounds like you put alot of work into it. Did you take notes during the process to help others through this process?

fuzzkill
Posts: 50
Joined: Sat Feb 04, 2017 10:19 pm

Re: Manual Transmission Conversion

Post by fuzzkill » Thu Mar 16, 2017 2:47 am

I'm about to start acquiring parts for the swap. Nice work!

Could you re-pin or remove/add wiring instead of changing the whole engine harness? Could you repurpose some of the wiring going to the original TCM for the MT sensors?

I did a bit of research and apparently there are differences in the Camaro TR6060 and the GXP TR6060, you didn't have any issues with length or shifter placement? The G8 board seems to say you need to use a GXP transmission (good luck finding one!).

TBH I think I can get a good deal on an LS3/TR6060 pullout from a Camaro. If the trans will work then I'm probably going to go ahead and order it and then start buying the smaller parts like the shifter, hydraulics, etc. Do you have any part numbers for the parts you got? Crossmember, linkage, pedal, etc.

Thanks!

kras007
Posts: 27
Joined: Sun Feb 26, 2017 6:54 am

Re: Manual Transmission Conversion

Post by kras007 » Mon Apr 17, 2017 11:55 am

It is possible to utilize the existing trans/engine harness. You would need to splice in the 7 manual trans connectors to that harness and then repin the bulkhead side. In my opinion its not worth all of that work. The GXP engine/man trans harness is around $250 and will be a clean install with a lot less labor messing around with the wiring.

You will want to save your time to make the other wiring changes that are necessary to complete the conversion. The other wiring changes can not be done by purchasing a new harness. Existing harnesses will need to be modified. Clutch pedal wire, vehicle speed sensor, cooling fans are a few of these that need to be worked.

Had no issue with alignment of the shifter. GXP two piece bell housing vs r6060 one piece bell housing seem to be dimensionally the same length. The only difference I see is that the two piece bell housing makes for a easier removal from the vehicle once its installed because you can access the bolts for the trans to bell housing much easier than the bolts from bell housing to engine.

cal30_sniper
Posts: 94
Joined: Thu Aug 04, 2016 6:17 pm

Re: Manual Transmission Conversion

Post by cal30_sniper » Wed Apr 19, 2017 1:34 pm

Would you be willing to post the wiring modifications/pinout diagrams that you used? You obviously put some serious time and effort into doing it right. It would save some others from having to fight the same battles you've already won.

Also, some of the GM part numbers you used might help some folks. After a quick look online, I see an engine harness for the G8 GXP, but no mention of transmission type, or different harnesses for automatic/manual cars. (form GMpartsdirect.com)
-2011 Caprice 9C1, 11k mile non-issue car
-1973 Firebird Formula, restoration in progress
-1986 C20 Suburban 454/5-speed, the toy hauler
-1991 BMW 325i
-2005 Jeep Grand Cherokee 4.7L, the wifemobile

kras007
Posts: 27
Joined: Sun Feb 26, 2017 6:54 am

Re: Manual Transmission Conversion

Post by kras007 » Sun Jul 09, 2017 5:33 pm

Sorry I have not responded in sometime now, I've been busy with other projects. Just wanted to forward along a video. The Caprice with manual trans and cam has been on the road now for a few months. The owner has enjoyed driving it and has no problems to report. Check the link below to a video the owner sent me of the Caprice out for a stroll. Even though he can't afford shoes he did say he is ready to put a supercharger on it. Looking forward to the next phase of work on this beast and getting it into the 600hp club. Lets encourage him!

https://www.youtube.com/watch?v=XSaHxvR ... e=youtu.be" onclick="window.open(this.href);return false;

Any of you ready for the conversion? Hit me up!

smwalker
Posts: 1393
Joined: Mon Jul 29, 2013 6:44 am
Location: Azusa,CA
Contact:

Re: Manual Transmission Conversion

Post by smwalker » Sun Jul 09, 2017 7:45 pm

Very Nice. But how am I supposed to hold my cheeseburger when I drive?
Steve Walker
Azusa, CA
'11 PPV 9C3 Huron White

Gerome
Posts: 322
Joined: Mon Jan 20, 2014 1:07 am

Re: Manual Transmission Conversion

Post by Gerome » Thu Jul 13, 2017 4:22 am

Just watched the video of your customer driving his Caprice banging gears barefoot . That ol boy is just rowing and relaxing lol . This swap is definitely to cool ! :D I need to start looking for a cheap 9c1 .

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