crash boxes

[tomslik]

anybody ever drive one of these on the street?
were they a big PIA or tolerable?

btw guys, if you have to ask what a crash box is, you're not old enough...

[58 Yeoman]

Had one in my 46 Ford truck that I drove as a daily driver for a while.  Four on the floor w/granny low.  Double clutch, no problem.

[av8]

Had one in my 46 Ford truck that I drove as a daily driver for a while.  Four on the floor w/granny low.  Double clutch, no problem.

HAVE one in my '48 F-1 and it's only mildly annoying when driving in heavy traffic. I'm replacing it with a T5 simply because I want the overdrive fifth gear.

[Crosley.In.AZ]

Crosley trany is full crash box.

After not driving it for a while ... it takes a bit to get back into not crashing it as you shift.

Women used to drive Crosleys when new, so I think you can learn tom

[tomslik]

Crosley trany is full crash box.

After not driving it for a while ... it takes a bit to get back into not crashing it as you shift.

Women used to drive Crosleys when new, so I think you can learn tom

uh, maybe we're not on the same page but maybe this'll help ya understand;
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7945683759&ssPageName=STRK:MEWA:IT

[Bob Paulin]

Tom:

Back in my teenage years, when the earth was still cooling - and Hot Rod Magazine actually featured technical articles that showed you how to do things yourself instead of five-page photo-essays on how to install their advertisers' products - I read an article about building your own "Crash Box" for drag racing.

Basically, it involved grinding out every other tooth on the synchro rings and collars allowing a clutchless - or "crash" shift.

The wider slot in the collar, coupled with the bigger gap between synchro ring teeth allowed you to "crash" the collar over the synchro without de-clutching - due to a much wider target area - while still gaining some benefit from the synchro ring speeding up the gear in order to match speeds while engaging it.

The synchro teeth on the gear itself remained, so there was no backlash once the collar was engaged, but with the modified synchro collar, you were only engaging every other synchro tooth on the gear.

We built one for the oval track, but really couldn't see the benefit of all that labor for single-shift starts and re-starts - in addition to nagging feeling that we had weakened the outer synchro collar (even though the tranny never blew) - so we never bothered again.

Also, Jericho - and others - now make transmissions with "dog" couplers  these days - which are much more substantial than ground-down synchronizer components, so a lot of upper-tier oval-trackers now use track-specific-gear-ratio Jerichos - or others - on both road-courses and oval-tracks.

The original Jerichos were designed for clutchless up- and down-shifting in road-racing....perhaps as an improvement on the early home-made drag racing "crash boxes" featured in HRM.

IIRC - The article suggested that if one of these "Crash Boxes" were to be built for the street, it should be driven - at all times - as though on the drag strip - with the appropriate, clutchless, aggressive,  "Crash Shifting".

Only YOU can determine whether or not that would be a PIA for YOU.

I believe a lot of the people responding here are refering to ANOTHER commonly accepted meaning of "Crash Box"  - a fully UN-synchronized manual transmission - which requires double-clutching to get the mating gears spinning the same speed prior to engaging them.

B.P.

[tomslik]

Tom:

Back in my teenage years, when the earth was still cooling - and Hot Rod Magazine actually featured technical articles that showed you how to do things yourself instead of five-page photo-essays on how to install their advertisers' products - I read an article about building your own "Crash Box" for drag racing.

Basically, it involved grinding out every other tooth on the synchro rings and collars allowing a clutchless - or "crash" shift.

The wider slot in the collar, coupled with the bigger gap between synchro ring teeth allowed you to "crash" the collar over the synchro without de-clutching - due to a much wider target area - while still gaining some benefit from the synchro ring speeding up the gear in order to match speeds while engaging it.

The synchro teeth on the gear itself remained, so there was no backlash once the collar was engaged, but with the modified synchro collar, you were only engaging every other synchro tooth on the gear.

We built one for the oval track, but really couldn't see the benefit of all that labor for single-shift starts and re-starts - in addition to nagging feeling that we had weakened the outer synchro collar (even though the tranny never blew) - so we never bothered again.

Also, Jericho - and others - now make transmissions with "dog" couplers  these days - which are much more substantial than ground-down synchronizer components, so a lot of upper-tier oval-trackers now use track-specific-gear-ratio Jerichos - or others - on both road-courses and oval-tracks.

The original Jerichos were designed for clutchless up- and down-shifting in road-racing....perhaps as an improvement on the early home-made drag racing "crash boxes" featured in HRM.

IIRC - The article suggested that if one of these "Crash Boxes" were to be built for the street, it should be driven - at all times - as though on the drag strip - with the appropriate, clutchless, aggressive,  "Crash Shifting".


pretty much how i drive    



Only YOU can determine whether or not that would be a PIA for YOU.

I believe a lot of the people responding here are refering to ANOTHER commonly accepted meaning of "Crash Box"  - a fully UN-synchronized manual transmission - which requires double-clutching to get the mating gears spinning the same speed prior to engaging them.

B.P.

i never knew it was to be "clutchless", always thought it was just for easier shifting under WFO throttle.

[Sean]

Jericho used to sell a clutchless version of a Rockcrusher. The article I read about them in stated that they used straight cut gears and modified synchro's. The straight cut gears were supposed to be stronger, along with allowing the clutchless shifts.

I thought that sounded like a good idea, but I haven't heard of them since that article and that was at least ten years ago...