custom crashbox???

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

shomtx95

Member
Joined
May 25, 2007
Messages
225
Reaction score
19
Location
wilkesboro,N.C.

AREA 91

PA SHO SHOP
Joined
Jul 17, 2002
Messages
5,349
Reaction score
1,003
Location
Area 91
Was doing some searching on shotimes today and came across something i have looked at a 100 times and never thought anything about it. It is doug lewis's old page about the pro fogger system.http://www.shotimes.com/php-bin/modules.php?op=modload&name=News&file=article&mode=thread&order=0&thold=0&sid=223about halfway down the page under transmission, it says Custom crashbox (every other tooth ground off the third gear synchro) WTF?? also what is a Quasi-Posi differential.

Grinding every other tooth off of the syncro will help in speed shifting at the drags.

As far as the Quasi-posi, I have no clue.
 

Pro*banshee

Active Member
Joined
Jan 2, 2008
Messages
222
Reaction score
49
Location
PA, 16066
Grinding every other tooth off of the syncro will help in speed shifting at the drags.

As far as the Quasi-posi, I have no clue.



Why didn't we grind the teeth off of mine? Get ready because when we do the upper 60k every third tooth is coming off that ******
 

gmorrell

Never been a noob...
Joined
Nov 28, 2000
Messages
806
Reaction score
540
Location
Colorado Springs, CO
Quasi-Posi was a SHOShop product that came about prior to the Quaife diff.

They took a standard MTX-IV differential, disassembled it and machined a few 10's of thou off the diff housing mating ******. When they put it back together, it compressed the sun gears fairly tightly together, which limited differential action - at least for a while until the mating surfaces wore out and the clearances opened back up.

Same effect as the Phantom Grip snake oil POS, but at least the Quasi-Posi got to keep all four side gears. Still a bad idea...

Removing synchro line-up teeth is a slick way to increase shifting speed, but at the expense of synchro life. The synchro teeth are considered wear surfaces, and removing every other one means that those that remain will wear out that much faster.
 
Last edited:

1995SHO9

FLEES ARE COMIN
Joined
Nov 25, 2007
Messages
1,360
Reaction score
327
Location
Carlisle PA
Hmm, learn somthing new everyday. So the QuasiPosi didn't work too well? Is there anyone on here that still has one and how is it working?
 

gmorrell

Never been a noob...
Joined
Nov 28, 2000
Messages
806
Reaction score
540
Location
Colorado Springs, CO
Oh, it worked; it was a nice accessory to help acceleration in straight lines, but it was no Quaife.

The extra prelaod on the outside faces of the sun gears meant that they were bearing into the diff's Aluminum case. Eventually it would wear itself back to a non-preloaded condition and act like an open diff again.
 
Last edited:
Back
Top