The Stovebolt Site Forums The Parking Lot Tons 'o Fun modified nv4500 to chevy cast bellhousing

I just got thru with a mod to my 67 c30. Using a 1/2 inch steel plate, and a turboglide adapter from dorman, with a ford mustang throwout bearing, I hooked up a 2000 chevy formerly hydrolic throwout bearing nv4500 to a cast iron bellhousing used by chevrolet from 1955 to 1972.Step 1, machine the hydrolic throwout bearing to fit the chevy bellhousing, cutting off the hydrolic tubes and the spring retainer tube.Step two. bore the steel plate to fit step ed nv4500 bearing retainer.The steel plate required countersinking two bolts to mount to the chevy bellhousing. step three drill holes to sandwich all three together.

Hy dwragon, could you post some pictures please "one picture is worth a thousand words, grasshopper"

If I knew how to get the pics out of my camera and onto the site, I would.

Hy dwragon, I know exactly what you mean, luckily for me my partner knows quite a bit about confusilators and digital cameras and stuff, I can turn this darned thing on, and hunt and peck with one intelligent finger on each hand, anything more than that is like the roof (over my head). I do hope you can learn how to post pictures, they're so much easier than trying to visualize from a description, good luck.

3B is right, any help with the NV4500 swap would be a real help!

If someone who can post the pictures will send me a PM with an email address, I will send them the pictures.

Well, to put it simply, this was not a simple adaptation. It took two plates for me to get it right, and even then, getting the holes alignment for drilling was still not perfect. In the end it was a very tight fit, pulled togather by the bolts. one of the things I forgot to mention was that I had to grind about 5 thousanths off of each side of the throwout bearing fork to make if work with the mustang throwout bearing, which replaced the stock t.o. bearing which was to small to fit on the hydrolic t.o. bearing tube.

OK I finally got the pictures on photobucket, go to the site and search ddwragonn, and then click on the user's profile. There are 8 pics posted.
The first shows the T.O. Bearing differances and the box with the part number.
the second shows the modifications to the hydrolic throwout bearing that no longer is.
The third shows the 1/2 steel plate on the bellhousing.
the fourth shows the turbohydromatic adapter from dorman installed in the crankshaft.

The 5th again shows the steel plate on the bellhousing, except this time it has the two countersunk (angled)allenhead bolts holding the plate to the bellhousing, with two bolts protruding through the plate.

The 6th shows the turboglide adaptor beside its box. the last two are the assembled adaptation, showing the bolts going thru various holes, including ones I had to drill in the transmission case. I had no problem bolting it to the engine and the input shaft goes into the adapter about 1/2 inch, close to factory as you can get without doing a million measurements to get an exact depth.

One thing that I would do differantly is that I would have countersunk the two protruding bolts in pic 5, as well as all 4 of the ones to the bellhousing. You can also use this modification on a standard aluminum truck bellhousing by countersinking the allenhead bolts in the steel plate.

The most expensive cost of the adaptation was the countersink drill bit, $30, (do not use a regular drill bit for this as the angle is not the same) and the centerpunches that I bought at harror fraight.

To all,

to make things easier, here is the url for dwragon's pictures
http://s1266.photobucket.com/profile/ddwragonn

For this operation, one shouldn't need any adapter plates, unless using a different input shaft.

1. Bore out retainer dia. in bellhousing to match the trans., or alternately, turn the retainer down some, and then bore out the bellhousing.

2. Put the two together, use a suitable transfer punch to transfer the bellhousing holes to the front of the trans.

3. Drill and tap suitable holes(.5"x13) in front of trans., make the bottom holes blind or seal them up w/ epoxy, etc., so one doesn't get a bath when removing.

4. Bolt them together using bolts from the inside of the bellhousing, requires bellhousing to be removed, or through bottom access plate if so equipped.

5. Do your clutch/throwout bearing details.

To "Roadmarks", Thank you for your assistance, I am sure everyone who reads the entire post will appreciate it.
As I originally posted, the subject was "Modified nv4500". This referse to the elimination of the hydrolic throwout bearing.
1, boring out the hole in the bell housing would severly effect the structural integrity of the casting.
2, The throw out bearing/torque tube bolts to the input shaft bearing retainer. Trying to turn this down enough to fit in the hole in the bell housing would, in effect, remove the area where the bolts hold the bearing retainer to the transmission housing.
3, Due to the design of the bearing retainer/torque tube, the input shaft tip to case is longer, ie, the input shaft would have to be shortened if the bell housing was mounted directly to the case. Additionally, I personally would not want to drill into a transmission case blindly.
Hope this helps clarify the post.