I purchased one of the surplus brand new 420's from Capitol Jeepers in Sacramento Ca. ... it requires a different shifter tower since it was a remote shift set up......They changed all forks and related parts into a cane shift tower, All work appears proffesional and all parts are indeed brand new.
When I put the tower on everything is smooth and all that until I start putting bolts in the top( requirs a slight bump forward) then neutral holding input and output shafts ( pipe wrench on 420 output yoke and 15 " crecent on input )becoimes very stff and it requires about 25ft lbs to turn. 3rd ,4th and reverse are the same way. In 2nd or first the tranny turns freely as it should. I have used dykem on forks to check for interference and polished down a casting number at top of 1st 2nd fork and nothing appears to be in the way.
Conclusion: the 1st 2nd fork is starting to engage 2nd gear and putting a drag on the synchro set up. I WILL want to use other gears then 1st 2nd and don"t want any problems.......or is this even a problem..??????? Is it part of some normal break in process???? I had one of these gear boxes in a 66 chevy truck and I remember that there was not realy much smooth or quiet about it.!!!!!!!!

ANY input greatly appreciated...... THANKS

Not a lot of help, but I have mine out at the moment, and it doesn't take a lot of effort to rotate it in any gear, and they all seem about the same. That's a stock shifter mechanism though.

David

It seems real likely if I simply elongate the mounting holes about .020 on the tower that I would let the tower mount up where it wants to work properly. I have shifted into 2nd, 3rd, 4th, reverse and lifted the tower straight off and all gears are meshed up properly. 1st gear won't allow this because of fork interference to case when in gear. Also when in this position of .020 to the rear the gear box turns over freely in all speeds and neutral as it should.
If anyone has any thought on this idea please post .


Thanks::D :emb:

Originally posted by wolfthing 2000
I purchased one of the surplus brand new 420's from Capitol Jeepers in Sacramento Ca. ... it requires a different shifter tower since it was a remote shift set up......They changed all forks and related parts into a cane shift tower, All work appears proffesional and all parts are indeed brand new.
When I put the tower on everything is smooth and all that until I start putting bolts in the top( requirs a slight bump forward) then neutral holding input and output shafts ( pipe wrench on 420 output yoke and 15 " crecent on input )becoimes very stff and it requires about 25ft lbs to turn. 3rd ,4th and reverse are the same way. In 2nd or first the tranny turns freely as it should. I have used dykem on forks to check for interference and polished down a casting number at top of 1st 2nd fork and nothing appears to be in the way.
Conclusion: the 1st 2nd fork is starting to engage 2nd gear and putting a drag on the synchro set up. I WILL want to use other gears then 1st 2nd and don"t want any problems.......or is this even a problem..??????? Is it part of some normal break in process???? I had one of these gear boxes in a 66 chevy truck and I remember that there was not realy much smooth or quiet about it.!!!!!!!!

ANY input greatly appreciated...... THANKS

I believe there is a change in top cover/tower assemblies. Something like early covers and late. I remember reading that if you switch covers from different year models, you may get shifting problems. It has been awhile since I researched all about the 420.
If you look at Novaks web site there are 3 different models or rebuild kits available, depending on the years of manufacture, this may have some relevance, as to changes that may have been made. The parts page is here: http://www.novak-adapt.com/catalog/sm420_parts.htm.
Look around, I could have read the info in a magazine, but I believe I spotted it on the web. Hope this helps. Andy

Think that was what was wrong with Rick Pewe's Jeep on the Ultimate Adveture if you follow the mags, he had to switch top covers. I don't remember exactly but I'm pretty sure it gave the year break downs in the article. He had trouble with third gear.

David

I seem to be getting close to solving this problem.....See my post on Three SM420s..............:)

:cool: Just to conclude on this subject , if anyone ever runs into the same situation, I elongated the holes just enough to let the tower set where it needed to ( only about .015 to .020) and then drilled 2 5/16 holes at diaganol corners on the tower and bolted body fit bolts and lock nuts through the tower and tranny case to act as dowels......locking the tower in position so it couldn't shift around.
The tranny works beautifuly!!!!!
Dave:cool:

If you ever deside to change the tower I have several differant years.....I believe that is the problem I've never experienced it myself but have read about it happening several times,looks like you've got it licked ;) ...
-Kerry

Originally posted by wolfthing 2000
:cool: The tranny works beautifuly!!!!!
Dave:cool:

I have wondered from time to time what ever became of this situation. Thanx for the up date.

:cool: Yep! A Whole lot of self reliance...a good old school engineered tranny....a whole lot of common scence and 30 some odd years working as a machinist......mix that with " I will make it work!!!!!" and the results always come out positive ( maybe not always the first time) .
Now I have a half dozen more SM 420s to go through and put a couple more good uns together for a few more upcoming projects.!!!!! GOOD TRANSMISSIONS!!!!!!!
Dave