Hey gang..
As most of you know, I chose the GearVendor option for an overdrive system for my Daytona. Well, I began the installation process and would like to document my experiences.

Vehicle: 1969 Charger Daytona
Tranny: 727 Torqueflite
Differential: 9.75 Dana (4.10)
GV unit: Model 3D0727

1. Here's the basic/components I received with the kit



1. Raise/secure vehicle and remove driveshaft




2. Position jack/support under transmission. I used the tranny pan with a scissor jack with a block of wood



3. Remove tranny rubber insulator and crossmember ( I didn't remove insulator from crossmember)



4. Place drain pan under tranny and remove inspection plate that covers tranny housing snap-ring



5. Disconnect/remove trannyspeedo gear assembly from tailshaft housing



6. Remove six bolts securing tailhousing to transmission



7. Use snap-ring pliers to spread snap-ring while pulling tailshaft housing off.



8. Clean gasket surface on tranny



9. Remove original lock pawl assembly out of original tailshaft housing and install into new GV tailshaft housing. Also remove the snap-ring and install it into the new GV unit.





10. Install GV tailshaft housing onto tranny tailshaft. I utilized two exhaust manifold studs to hold the new gasket in place to help with the GV tailshaft housing installation. Worked out great. Once a couple of the original bolts are installed, you can remove the studs.




11. On my Daytona, there was a TTI exhaust system. The center h-pipe clamp was positioned with the nuts towards the back. This created a forward movement obstruction for the tailshaft housing. Simple solution was to reverse the clamp.





12. Install snap-ring cover gasket, cover and crossmember. Also, in my case with a center console, install the shifter rod bracket.




13. Verify the coupler is seated fully forward touching the tailshaft. Lightly grease the outside of the coupler, bushing, seal then slip the coupler back into the tailshaft housing. There shouldn't be any binding. The coupler is positioned in the housing for shipping purposes. Adjust the end play. I accomplished this by utilizing a straight edge, slipped two of the numerous supplied shims between the coupler and straight edge and then taking a measurement. I ended up with .013 clearance. The tech at GearVendor told me this was a proper technique and have a tolerance between 0 - 0.15. Do not place grease in the coupler to hold shims when reinstalling. This will compromise the end play reading. The shims are to be installed into the coupler on the tailshaft side, not the overdrive unit side.



14. Unfortunately, the clearance issue that "supposedly" was fixed, isn't. The speedo assembly typically was the culprit, but this, for me, was an issue of the overdrive housing. So, yes, I "made" room. I took my pickle fork since it has a solid round handle and use it with a sledgehammer to curve the floor pan inwards. It worked out great I do have to say. It made a nice smooth modification. The white grease pencil markings are the areas that were touched by the overdrive unit. I also ground down the two areas of the overdrive unit that touched the floorpan. I basically rounded down the peaks of the unit.






15. Install overdrive gasket with lettering facing tailshaft housing.



16. Slide yoke onto shaft of overdrive unit and then position unit onto housing.







17. Secure overdrive unit with the eight 1/4 20-inch locknuts/washers

18. Install supplied speedometer cable adaptor.



19. Install signal generator to cable adaptor then vehicle's original speedometer cable to signal generator.



20. I used a cable loop to secure the speedo-adpator and solenoid harness. Had to do this to keep wires away from h-pipe.



21. Driveshaft modification. Based on the dimensions, I had to shorten my driveshaft 14". I used on of my spare driveshafts, but unfortunately, the inner diameter (ID) of the driveshaft won't facilitate the installation/welding of the foreard yoke. This yoke was to be a match for the GV supplied driveshaft tranny yoke. So, I had to have the driveshaft service company make one from scratch. This will probably be the case for most Mopar driveshaft modifications. I got new u-joints and the assembly high-speed balanced. Brought it home, but unfortunately, the dang thing was about an 1" too long !!!! So, I'll have to take it back Monday.. Bummer, I was hoping to have it installed this weekend.

21a. original driveshaft measurement. I used a spare 727 I had for the measurements with my original driveshaft. Length to centerline of u-joint (21.5")




21b. GV complete unit (35.5")




21c. At the shop




21d. About an inch too long.. :'(



22. I mounted the electronics behind the kick panel. It fit rather nicely to be honest.



23. I decided I didn't want to permanently mount the selector switch and status light. I made a plate and attached it to the vent box under the dash. That way, the velco adhesive wouldn't be on the vent box. From what I gather, most driving will be in the "auto" mode, so there will not be a need to change the selection switch numerous times.



24. Here's the kickpanel back on. Would never know the electronic autodrive control box is back there. Also, the wire you see is the foot switch. Instead of mounting it on the floor, I'm going to place a toggle switch inconspicuously under the dash.



What I have to do now is fill up the overdrive unit with Dexron II ATF. Never use synthetic or additives. After that, replace the exhaust flange-to-manifold gaskets and get the driveshaft fixed.. After which, test drive time..........

Update: Jan.07, 2011


25. OK, got the driveshaft back from the shop. The dimension they needed was 40" from GV overdrive unit output seal to forward most portion of the yoke going into the differential.



26. Next is filling up the GV unit with Gear Lube. Here is the access/fill hole.




27. Here I'm finishing up with the fluid.
Edit: GV's update on fluid is either GM# 12346190, or Mopar #0487-4459, I will update the picture........ I used the Mopar brand. It is Gear Lube, clear



28. Pump works pretty good - The ATF was installed, then removed when I discovered through and GV update I needed to use the previously mentioned Mopar Gear Lube


I'll continue this later on this weekend, I have Guard Duty this weekend, so won't be able to mess around with it much...

Hope this helps anyone in the future with a GV install. Update: Jan.07, 2011