GEAR VENDORS overdrive, same as units

[IPM]

fitted to volvo cars and other european cars. I was shocked when I looked at a gear vendors overdrive and quickly noted it's the same basic unit fitted to the '80's vintage volvo cars. Heck I got a dead volvo unit sitting in the garage. Compared to that one as well.

I understand how the 1:1 ratio could hold up under the strain of a 454 in a motorhome since it's just two drums pressed tightly together to lock the shafts, no gears turning. But man that's alot of load for those planetary gears to take when in overdrive.

Question one: Anyone know what the failure rate is for gear vendor overdrives?

Qustion two: Anyone simply mount a unit from a volvo on the back of their turbo 400? yea it would be easier to get the pieces less the actual drive from gear vendor to avoid fabrication of adapters. But I can get a good used unit from a volvo for under $50.

[74Argosy24MH]

Call Gear Vendors and ask if they ever made ODs for Volvo. I doubt it though, I have a US Gear and there is no way it would fit under a Volvo without some tall tires and a big hammer to beat the floor up about 6 inches.

Along with the trans adapter you are going to have to mate the input of the od to the trans output, get a tailshaft (and cover) that will mate to the u joints on the drive shaft and od output shaft. Lots of splines to deal with.

John

[IPM]

Hey I found it on their web site. They made over 1 million overdrives for volvo. I measured height of broken unit on my bench at ~10".

Instead of mounting to the rear of the transmission, maybe mount independantly. It's already got it;s own output flange and just cut off matching drive shaft to match and weld to new drive shaft. You gotta make a new driveshaft anyway.

For input flange, maybe cut off donor tranny output shaft and weld to neckdown portion of an oem shaft at center bearing support location.

To hange the thing, simple plate steel with the 8 mounting holes drilled, plus one in center for faricated input shaft.........................

[74Argosy24MH]

The US Gear is 12-13" It sure would be a lot easier to mount it seperately than than find all the right parts. Keep it as close to the trans as possible, smaller angles mean less wear on the u joints. Post some pictures when you get it done, sounds like a good way to get od.

John

[overlander63]

Originally Posted by 74Argosy24MH

The US Gear is 12-13" It sure would be a lot easier to mount it seperately than than find all the right parts. Keep it as close to the trans as possible, smaller angles mean less wear on the u joints. Post some pictures when you get it done, sounds like a good way to get od.

John

If anyone does this, the Volvo OD unit will engage with a simple toggle switch. I did this to an old DL I had, it worked well.
Terry

[mcneon]

Guys, I had one of those ODs in a '70s Volvo, and I'm thinking there's no way the Volvo unit will handle the torque. It might be okay in direct drive, but the planetary gears would surely melt under the stress in OD. The 454/502 has to put out 3-4 times the torque of a 2-liter Volvo, and we have a similar increase in vehicle weight, too.

The Volvo unit has an integral hydraulic pump like an automatic transmission, so its torque capacity in overdrive is related to input shaft speed. This also might be a problem on a slower-turning V8.

JMHO
Bob

[IPM]

Yes, I'm concerned as well regarding the torque. But it looks exactly the same size as the new units. There's not that much more room inside for larger planetary gears.

The new units have a pump as well and looks like it suppost to drop overdrive when pressures drop around approx. 22mph. Don't take that as a fact, read it on another forum (4x4's).

Don't hold you're breath regarding me building this. I've gone back to college after working 20+ years as an engineer. Have a practical exam in 90 minutes (yep I studied first before view this). Going to medical school to become an RN. Why? 1) Few to no jobs because there are few factories left in America. 2) For remaining factories, following the golden rule or faith in Christ is now considered a weakness. Any how .......... I deviate. Heck I need to reseal the sink drain,

Still concerned about the torque capacity of the volvo unit. I may call gear vendor if time permits......

Mike

[uncleneal]

I've read somewhere that the GV unit is the same as the Volvo unit, and that GV won't sell adaptors or parts separatly for that reason. Volvo's are pretty tough, it may be stronger than it looks and stronger than it has to be.
Why not mount it to the differential and eliminate one set of u-joints?
Neal

[IPM]

Makes sense regarding the adapters. Yea, the vovlo overdrove seemed to not fail often, just the automatic box ahead of it.

Yep could mount to diff, but then got problem of shaft alignment (when mounting overdrive) or the bearings both ends will be under load/stress. I had enough shaft alignment woes in the factories. But then joints eventually failed as well. I guess pick your future repair preference?

Going camping tomorrow!! Love that big block

[IPM]

Interesting threads..........

http://www.airforums.com/forum...ead.php?t=3966

http://www.airforums.com/forum...ead.php?t=3966

http://www.airforums.com/forum...ead.php?t=4187

http://www.airforums.com/forum...read.php?t=337

[IPM]

Hey, Look here, remote mounting of the gear vendor. And I have nothing to do with this auction.

http://cgi.ebay.com/ebaymotors/ws/eB...spagename=WDVW

[IPM]

http://cgi.ebay.com/ebaymotors/ws/eB...tem=2474742126

[IPM]

googled j overdrive volvo and found:

Type J Overdrive An overdrive unit capable of handling up to 185 ft.lb. of continuous engine torque; identification plate on side of overdrive unit.
Type P Overdrive An overdrive unit capable of handling more engine power (torque) than Type J. First installed on manual trans 1986 700s with B230F-Turbo. It can handle continuous engine torque of 220 ft.lb. (30ONM). Identification plate on side of overdrive unit.

I think these are a light duty application, and unless some smart fellow can think of a modification, such as increasing clamping force for drums, it will not work. But sure would be interesting on other applications (such as the toad).