Jump to content

Bellcrank Repair


Rodjaxx

Recommended Posts

I?m posting this to see what other Reatta owners think of my repair of the headlight Bellcrank.

I recently bought a 90 with bad Bellcranks (the slotted hole was completely wore out and it spun freely on the shaft) and I?m a retired Tool and Die Maker with a small machine shop with a CNC mill.

I wrote a program to make a ¼? thick steel insert that has the slotted hole (.375 dia. with .265 flats) with the outside approximately 5/8? x 3/4?. I then did a program for the old Bellcrank to make a pocket to match the insert. (.0005 press)

This setup works well, with no problems and should last the rest of my life.

I also made a fixture to locate and clamp the motor/gear housing and a program to remove, resize the hole for a 10-32 screw for two screws that broke while disassembling for bushing replacement.

If anybody has old bellcranks that would sell to me for $5.00 a pair + shipping please email me at rodjaxx@msn.com

I would like to make up about 20 pairs and offer them for sale at $25.00 each or $40.00 a pair.

I?m sure the all steel replacement I see here will work just as well, they don?t look stock.

post-37940-143137893847_thumb.jpg

Link to comment
Share on other sites

Looks like a good fix, neat job and almost stock. Your projected pricing seems reasonable. Many people on the forum, (myself included), have used Barney's all steel cranks and are very pleased.

QUOTE:I also made a fixture to locate and clamp the motor/gear housing and a program to remove, resize the hole for a 10-32 screw for two screws that broke while disassembling for bushing replacement.

Sounds good too, any Pics available??

Link to comment
Share on other sites

Rodjaxx......it looks like a great fix. Not many people have those tools.

You might want to do the bellcranks on an exchange basis after you get a few bad ones to build up stock. Sell the bellcrank with a core charge and then the buyer would send you the old ones.

I looked at several fixes before going with the reworked steel bellcrank and many would work but had dis-advantages. I also did not have a CNC mill.

Removing the broken screws are a problem. The problem is caused by GM using thread forming screws. There is no clearance between the screw and the casting and any amount of moisture will lock them in place. I use carbide drills because the thread forming screws are much harder than regular screws and Wal-Mart drills will not last one hole.

Have you considered a fix for the convertible visor clips?

Link to comment
Share on other sites

  • 2 weeks later...

I posted this a while back when your forced to do an immediate zero cost fix and it does take a little over an hour for each bellcrank fix. It involves carefully (precision) filing two new flats on the bellcranks and hacksawing and cutting two steel shim inserts. After 9 months and 9,000 miles the bellcranks are still wedged on tight. You must use a dial or digital caliper for measurement to make it work. I don't remember the dimensions but I used two 1/4 by 1/16 inch thick steel shim stock cut to around 3/8 inch length. The length has to be a little shorter than the flat to prevent the nut from locking against the shim instead of the bellcrank. You have to be careful because the motor shaft flat has about a .010 inch slope on the flats referencing from one flat to the other with the smaller dimension near the threaded end. The original bellcrank appears it was designed to be wedged onto the tapered shaft with the nut to insure no looseness to prevent wear from movement. With a .25 inch wide file two new opposing flats on the bellcranks for a spacing including size of the motor shaft flat spacing plus two shims. Frequently check the size to make sure the flats are almost parallel except you have to file in the .010 inch narrower spacing on the bolt side of the bellcrank verses 3/8 inch inward shooting for about a .003 inch interference fit with the proper slope. So when the bell crank is reinstalled with the shim stock it wedges very tightly against the motor shaft flats. I assembled with Loctite being careful it doesn't migrate into the motor bearing.

When filing do a test fit a couple times to make sure you don't over shoot. If you do overshoot go to thicker shim stock. Also keep the flat with very close to the .25 inch shim stock width. You could use a drop of super glue or Loctite under the shims and let cure to help hold the shims in place for assembly. I hope my wording makes sense. If you don't need an immediate fix, it's easier to buy Barney's bellcranks.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...