Trust 6 Speed Dog Boxes

[Madden]

I have just brought a trust 6 speed straight cut dog box for really cheap but in need of a rebuild.

I have done a search on here and alot of you guys seem to have knowledge on them and hopefully some spares.

It came out of an ex group N race car in Japan and was rebuilt last year but it has gone pop again. The previous owner snapped the layshaft of with 5th and 6th gears still attached.

So i brought it took it apart and it has snapped it again????? Any ideas why it keeps happening?

The worst bit is the layshaft you are looking at was the last one available brand new from the stock of parts that quaife have.

It has also done 4th gear. It has lost a couple of teeth on the mainshaft and slightly messed the lay shaft gear up at the same time.

The reverse idler gear has also taken a beating from where it has been trying to select.

Also i have never driven a dog box but have done a search and there was alot of tips from you guys. Should i bother to replace this gear as i know they dont last long until they look like this?

Any info or help would be great guys cheers

[SteveL]

So i brought it took it apart and it has snapped it again????? Any ideas why it keeps happening?

Without examining the broken parts properly (ie microscope and maybe SEM) I can't be absolutely certain, of course, but looking at the photo's I'd say it's odds-on the shaft has failed due to cracking (probably fatigue) at the splines at the change-in-section where the shaft passes through the bearing. I'm guessing the other shaft failed in the same place (??). If that's the case, it's a design issue, and any replacement shaft of the same design will do exactly the same thing (eventually...). Any replacement shaft should be re-designed to eliminate the splines at that location. Of course, that might be quite difficult.

As I said, I'd need to examine the parts to be certain.

[T04GTR]

so the race car this came out of... do you know if the shifter and forks are ok? just saying that it may have selected 2 gears at once..

i find it hard to believe that they have splines running into a bearing as well.

where it is broken are the edges of the break shiny? or is there any colored stains at the break? or is it a uniform matt finish where its broken..

a close up of the snapped bit would be helpfull.

for parts you need to contact quaife in the uk.

[Madden]

Cheers for the replys

Yea quaife no longer have any layshafts left over. The last one was sold to the previous owner and its the one you see now snapped again They are not planning on making any either so if they do it will be a one off for me and could take up to 4 months.

I'm not sure if the selectors are ok as there must be something wrong for it to happen twice under normal drivng conditions. I see what you are saying about selecting two gears at once. I did find the selector gate lose but that wouldn't cause this.

Yea it does seem that the splines run through the bearing too, which is crazy.

I will get a close up of the snapped shaft in a bit.

Thanks alot for your help so keep it coming as the guy in the uk gave up on these gearboxes years ago.

Edited January 16, 2009 by Madden

[Madden]

Here are the close ups of the broken layshaft

[Madden]

Been out there today to strip the shaft out of the box and to strip it down.

Nice peice of kit and not that heavy

There are still two bits that i want to save on it. One it where the bearings sits and goes through the center plate. The other is where 6th gear sits on its bearing. I cant remove them due to the damage to the shaft. It doesn't look like the shaft just gave up for no reason. Check the photo out and follow the splines to where it snapped. Twisted or what.

And here is the 4th gear off the layshaft. Looks abit damaged to me. The 4th on the mainshaft lost some teeth so i guess its eaten this gear slightly.

[turboedsloth]

far out looks like that box has copped a hiding. ive seen axles twist like that but not a mainshaft. good luck tryin to repair it

[Madden]

Yea it came out of a Group N race car from Japan. It was only rebuilt about 6 months ago for the same reason and it has only seem road work.

And its only the layshaft

Tad annoying that the parts are un available

Edited January 19, 2009 by Madden

[Angus Smart]

Wow,

Very interesting, they almost look like my photos!!! i had the exact same box in my car from japan, about a month later no more 5th and 6th..

i ended up going thru Quaife also.. they were pretty good to deal with! i would have only bought that shaft about a year or so ago from them, I sold the box onto Jetman on this forum. whom i think snapped the imput shaft pretty soon after it happened.. (tho it was bent somewhere down the line of gearbox shops looking at building it..)

i think i also spoke to someone locally about making up parts. try albins off road in Victoria http://www.albinsgear.com.au/

they said they would be able to make me up something..

Edited January 19, 2009 by Angus Smart

[Madden]

So you had the same problem too.

It seems to be way to common.

Quaife have no more stocks of parts anymore so it looks like i have to get one made up and hopefully stronger.

Cheers for the help mate

[T88 ON BOARD]

I just recently Broke my trust 6 speed Dogbox aswell...

It was freshly rebuilt with original parts and didn't last long at all.

Not entirely sure what went wrong though still havent pulled it out to have a peak inside...I was hard on boost in 3rd when bang..Rattling and metal on metal noises....I think i broke a selector fork but can only know for sure once i pull it apart...I cant select any gears its like nothing is in the housing!

I think the trust box's are getting old..if mine is hard to fix or costs too much ill prob go for the ppg set up instead might be a wise investment for ya Madden

I miss the winding noise

[Angus Smart]

i may still have alot of communication with the guys at Quaife, they spoke to me in detail about what problems they had whit these boxes.

mainly the reverse ideler, he simply put the reverse gear will always wear out, they focused on making 6 strong forward gears, now the gears themselves are pretty strong, where that shaft snapps is another problem, i was led to believe it was caused from a bent or loose selector fork selevting two gears at once. not too sure who told me that it may have been quaife...

[Roy]

I just recently Broke my trust 6 speed Dogbox aswell...

It was freshly rebuilt with original parts and didn't last long at all.

Not entirely sure what went wrong though still havent pulled it out to have a peak inside...I was hard on boost in 3rd when bang..Rattling and metal on metal noises....I think i broke a selector fork but can only know for sure once i pull it apart...I cant select any gears its like nothing is in the housing!

I think the trust box's are getting old..if mine is hard to fix or costs too much ill prob go for the ppg set up instead might be a wise investment for ya Madden

I miss the winding noise

If anybody is looking to sell their broken or functionng Trust box then PM me. I am sure they will be ok behind an RB20 I am hunting high and low for a gearbox at the right price. I dont see the sense in doing a $2500 conversion for an RB25 box when i cannot shift any quicker, the box is heavier etc etc when if i can roll a few more old ladies may be able to stretch the budget to 5-6k since i am staying with a std RB20

I found http://www.gearboxman.co.uk/ pretty helpful with some enquiries a while back

[T88 ON BOARD]

Andrew once the box is pulled a part and i find out what is the problem ill give you a call....if you could contact quaife on my behalf to see if they can still supply the parts needed that would be awesome!!!

In saying that i have a small box full of spare gears and selector forks so i may be in luck lol...

Roy my box may be for sale if its too much of a hassle for me to fix as ill prob go for the new ppg sequential

[T88 ON BOARD]

In saying all this I was Running a OS Quad Plate...That may have help brake the dogbox...

that clutch was only used as i had it laying around and was in need of a clutch...Will go back to a twin or tripple

[T04GTR]

yeah for a main shaft to twist like that is had to selected 2 gears at once. iether that happens or the gears break and the casing blows apart (ppg style)

its a shame. it may be woth while contacting modena or par to reproduce a new shaft.... anyone can do it, but for reasonable money is another story

[555kkk]

i just bought a trust sequential 6 speed , should i service the box and have the selector checked ?

know anybody in brisbane who specializes in these boxes ?

[Fair Dinkum]

Thats what you get for buying Jap crap.....they are cheaper for a reason everything the Japs make are to light for our conditions.. Get a PPG and forget it....

[T88 ON BOARD]

Thats what you get for buying Jap crap.....they are cheaper for a reason everything the Japs make are to light for our conditions.. Get a PPG and forget it....

huh......to light for our conditions?? In what way? what do you mean?

Trust 6 speed is not Jap its made by Quaife in England just branded Trust

I agree the ppg is a new designed gearbox so its gotta be better

[T04GTR]

yes all true, but. unforntunatly with a dog box you do need to crack test the parts. its just a fact of life. you smash something with a hammer for a year or soo it will crack. just when is the gamble.

after seeing this im gonna get my ppg straight cut a servive i think...