Read End Interchangability

[.45Cole]

I have an 87 VR with a decel gear whining that I'm 90% positive is a busted pinion nut. I'm wondering what will swap with the 1300 rears, will a second gen swap? I'm assuming that the 120 VR and Vmax will not swap I(maybe just the pinion?). I'd like to swap entire rears as I've got a trio coming and don't have time to monkey around.

 

i hear that the nut keeps the mesh correct on the gears, and when busted allows the mesh to slip a little on decel causing the whine. Everything is under spring t4ension and there isn't anywhere for the nut to go so I've been riding it, but I'd like to get it fixed to clear my mind.

[luvmy40]

I was under the impression that the V Max rear end was a direct swap. Or, that with a special tool the guts can be changed out to retain the Venture pumpkin.

 

I'm sure someone who has done this chime in soon.

Edited August 5, 2018 by luvmy40
typo

[CaseyJ955]

Gen1 Vmax pumpkins do install on the gen1 Venture. The functional difference will be the Vmax gears are lower and will change your overall ratios. If your an open road guy like me that might not be to your liking, but if your more on surface streets or spend time in traffic than you may really like it. Acceleration will improve at the cost of higher RPM at highway speeds. IIRC the difference is 3.33 vs 3.66 so about 10% difference.

 

A non functional difference is on the Vmax one of the shocks mounts to the pumpkin, so there will be a hole cast into the housing for that lower shock mount. Its only an esthetic difference going onto a Venture and wont effect bolting up. Thats only an issue if your putting a Venture pumpkin onto a Vmax. Some Vmax guys do this to improve highway cruising but it neuters that brutal burst of acceleration. I almost did the swap on my Vmax but because of the shock mount the easiest way for a Vmax guy to do it is to rent the gear puller Sean Morley and swap the gears into the correct housing. Venture with Vmax pumpkin, fairly simple and peppier acceleration.

 

I have an extra pumpkin off an 85 Vmax if you need any pics or measurements let me know. When I researched it previously I came up with gen1 VMX interchanges to gen1 XVZ. I hope someone that has actually done the job verifies, and I know its been done.

 

If you cant find a puller email Sean at one2dmax@aol.com. Some years Venture have an untapped shock mount but cant recall which, but from Vmax to Venture it should not matter to you. Im 98.975% sure you can bolt a pumpkin from any gen1 Vmax right on. Last I knew he had a puller he rented out via mail and would probably know off the top of head if your going to run into compatibility issues.

Edited August 5, 2018 by CaseyJ955

[.45Cole]

Thanks for the replies, I know the 1200 and 1300 venture rear ends look different, and cost different on fleabay, so I figured they didn't bolt up (but it makes sense that yami wouldn't change a good thing and retool).

 

If somebody knows for sure if a 1200 diff will bold up to the 1300 please speak up, and I'll just buy one on ebay and be done with it,

[VanRiver]

I have personally swapped out 2 Vmax diffs on to my First Gen MKII 1300cc Ventures. It is a great upgrade and was completely plug and play. They just bolt right in. I don't believe the first gen MKI 1200cc Venture diff can be swapped into an MKII 1300 Venture. The Diff case design is completely different, but I could be wrong.

 

To be safe for your project I would recommend that you get a replacement Diff off of eBay from another First gen MKII 1300 Venture or spend a few more dollars and get a First Gen Vmax diff which will give you a different gear ratio with a bit more power off the line. It will save you a whole bunch of problems and make your swap much easier rather than fiddling with different diffs requiring shims or changing ring gears etc to make them fit. Just my opinion of course.

[MiCarl]

The only difference between a MKII and 2nd gen finals is the 2nd gen has a hole machined for the speedometer sensor. I had a 2nd gen final on my 89 for awhile, just made a block off plate and gasket for it. Of course if you get the sensor with it you can just cut the wire off......