I just got my new GV overdrive unit, it looks very cool. But on quick inspection i see that the rear seal for the drive shaft yoke looks like its held in with a radaitor hose clamp with side tabs that bend over the back side of the seal to keep it in?????? I called them to ask why and was told they have been doing this for a long time as an extra precaution. Now Im not a professional mechanic so i have not seen that many trans tail shaft housings. The ones i have worked on, the seal fit in VERY snuggly and I have not ever heard of them coming out, not to say it couldnt happen. Im just worried that i got a housing that was machined incorrectly so the seal was not a tight fit and rather than send it back to the foundry or who ever cast them they just did this jicky fix to get rid of it.
So I havnt inspected it throughly, but this weekend im going to pull the hose clamp off and see how tight or loose the seal is. If its loose I would say someone screwed up machining it, theres no reason why they couldnt machine it to fit the seal properly.
Does anyone here have a GV unit? If so does yours have this big hose clamp holding in the rear seal? If thats the case, as complex as this unit is I would say someone machined it wrong and i dont want a "rigged fix" unit that i just paid $2500. for.
To be continued
Steve

 

Ok does anyone here know someone with a GV overdrive unit?

Steve

 

I don't have one, but looking at the images on their web site, it appears to me the clamp is shown on the images for several models which would appear it is standard.

Jeff

 

I have one but it is an older unit. Here are some pictures.... seems the newer ones have the clamp


Johann

 

How does this work? Is it like a 6 speed auto? Does it shift to a gear in between 1st and 2nd and 2nd and 3rd then to an OD? Any negatives to the way it drives?

 

I am very curious too. Is there any advantages vs. 200r4 or similar?

 

I have both setups, In my opinion each has there advantage the 2004R has a deeper overdrive (.67) and can be locked up and the GV has a (.78) overdrive for starters.

 

GV unit is bullet proof, T200R4 can be built strong but i think not as strong as a GV. GV is rated to 1200 HP and has a 2 year guarantee even if its on a race car. I did alot of reading before i made my decision and almost bought a 200R. The GV has no TV cable to worry about adjusting. So for me a GV behind a Turbo 400 is about as strong as it gets. The T200 does have a nicer final ratio I think, .67 but with my 3.90 gear he said my final will be 3.04. Thats not a bad highway gear and its strong as hell. Go to their site theres alot of info.
and last The T200 I was looking at from 2 different builders was $3000. the GV was $2500. for what I think will outlast the 200 by a long shot.

 

This GV solution is very appealing. Please post your experience with the installation and degree of satisfaction with the end result. It's certainly on my wish list. - Steven

 

Is there any issues with installing the GV unit? Do you have to cut the floor to get it to fit?
Now you got me very interested.
The estimate I got from CK was almost $3500 with torque converter, carburetor adapter for the TV cable and shipping.

 

Yes its almost like a 6 speed, each gear has overdrive capability. There are no issues with it as far as I know, but I havnt used it yet. Every thing I have read about them is positive. You don't have to cut the floor so im told. For an A body they mill a little more of the trans mount surface to lower it just a bit, but you still have to knock 2 small dimples in the tunnel for the top 2 bolts on the back end of the OD to clear. It comes with everything including a new drive shaft yoke, the drive shaft will need to be shortened some and balanced.
Yeah CK also quoted me almost $3500 too, $1000 more than the GV and probably not half as strong.
Also with the GV it weighs about 40 lbs, so that and the T400 will be heavier than a T200 but im not counting calories here, I don't care. It wont be a drag strip car, it will be fast enough for me....I hope


Steve

 

Thank you Steve. I am definitely look into this.

 

X2, I was looking into this as an alternative to an OD trans also.

 

I'd love to hear about the final install and how it works/runs. I'm thinking of going this route also on my 66.

 

I have a Laycock unit out of a suburban. Controls and overdrive no adaptor if anyone is interested. 600.00 I bought this set up for the adaptor to use on a GV I bought previously.

 

Well thanks for all the replies, I hope it works as good as they say. But don't hold your breath I still have quite a ways to go before it will be put into use. Im trying to sell this other 67 to free up some space in my shop. Its amazing how much room 2 67's and one Vette take up. I really don't want to put the other 67 outside but then it probably sat outside a long time before I got it. Anyway I plan to build a rotisserie for the one im building, so I still have some time before the GV is tested.


Steve

 

Another advantage of the GV setup over the 200r4: WOT shifts into OD.

 

How does it shift? Does it shift automatically? Can you put it in drive and go?

 

Fwiw I have never ran one but looks at some of the guys doing hot rods drag week. There are plenty of high hp cars I'm talking well over 1000 hp running the gv units. I think a unit behinds the th400 is plenty stout over the 200r4.

 

Steve,
I have a 66 442 with the GV and THM400. We had to raise the transmission tunnel about 1 inch to the end of the console and fabricate a new transmission bracket. The drive train is assembled with a shortened driveshaft, but the car is not quite ready to run - probably 2 months to go. I'll post some more pictures this evening. Also check out some of the details at www.classiccarsofhouston.com and go to their Facebook link.

Ray

 

my father and I are running a G/V . 1967 F85 , 425 toro , th350 , and a 3.55 rear . Had to massage the floor , add adj. upper rear control arms to get the drive shaft angle . It was all worth it . The 3.55 gets knocked down to 2.73 . Looking into a shifter to make the gear splitting easier than the column shift and 2nd high beam switch . We did 13.2 @102 mph in 2nd over . Still had 2 gears to go .

 

these GV fit in 71 without any problems? and the cost for them is 2500 ?

 

I just purchased mine for my 66 with a TH400. Price is closer to $2700

 

Bought mine 18 months ago - with shipping and tax it was $3200.

 

2004r will shift into od at wot. Or at least mine will.

Any pix of this gv install? How much power are you planning to try to put through it?
When you adjust the upper arms how does this affect traction? wheel hop?

 

I have a GV behind an M20 in a 70 vista and we had to raise the floor brace and tunnel about an inch. The salesman said "oh you have to modify the crossmember didn't you get those papers in the box". I had them fax me the missing pages and even with the crossmember mods it still wasn't going to fit without modifying the floor and tunnel. If your not comfortable with reworking the floor Id'e beware of the "you just dimple the floor in two places" line or the "oh you have to modify the crossmember" line.