MTA4 S28 Gearbox

[ollietheox]

Stripped some gear on my S28.  Replaced the worn parts, but now only have forward drive and no reverse (and before anyone says about not needing reverse........you haven't seen my driving).  Anyone ever come across this or know what I've done wrong?  Everything seems to have gone back in the right place, just cant engage reverse.

 

Any help is greatly appreciated.

[walters]

is that the thunder tiger monster truck i use to have one it was my drive pin were snaping

Edited May 11, 2013 by walters

[ollietheox]

Yep

[walters]

check your drive pins mate

[jordan_bench10]

Common fault drive pins or the adhustment isnt set right

[ollietheox]

All pins present and correct and re-thread locked.

[Rich8]

First check if you can engage reverse by sliding the selector arm by hand.

If it engages by hand, then it's just your aux servo not doing as it's told, or the linkage nneeds adjusting.

If it won't engage by hand then you might have to take the gearbox apart again to investigate.

[ollietheox]

That's the problem, cant slide it by hand.  Had it open twice and cannot for the life of me figure out what's wrong. 

[Arron421]

s28 gearbox is a waste of time will just keep happening. save your money and buy the s50 one will have no issues.

[ollietheox]

If I had 70 bucks to spend on an S50 box, then I would.  Considering the gears are only 5 bucks to replace, think I'll stick to tearing out what little hair I have left.

[MrPug]

Hmm I don't have much experience with the forward/reverse set of gears as most of the time I'm chucking them out and putting a forward-only kit into the transmission. I do however have a link to the wonderful forum that is MonsterGT.com. They have a section on the forward/reverse here, but typically that section doesn't really tell you much :

 

http://monstergt.com/articles/transmission_shifting_reverse.php

[ollietheox]

That's a start mate.  Many thanks.

[the-badger]

if i remmember right the thundertiger box is simmilar to the t maxx gearbox and the selectors are a pain in the maxxes as well. check if the selector fork is in the right grooves on the gear and chech the selector itself for play or dammage, on the t maxx they have snap in pegs that act as the wear point on the selector and theese have a habit of falling off.

 

http://www.todoomodelisme.com/fiches/pdf/

 heres a link to a page containing the exploded view of a mta4 box hope this helps

 

http://traxxas.com/products/models/nitro/49104tmaxxclassic-downloads

this is a link to the t maxx gearbox it might help as they use the same selector fork design

[ollietheox]

Awsome....cheers Badge.   Will have a crack at this on the weekend.  Watch this space (or the FS thread for a S28 roller).

[MrPug]

I'll take a look in my parts box, but I think I've still got the whole reverse shaft with all the gears on it from when I FOC'd my electric MTA4.

Let me know what you find in your transmission and I could sort you out with some spares maybe.

[ollietheox]

Any chance you could take a pic of it if its still intact? 

[MrPug]

I already took a picture of it when I removed it from the box.. its the one in this pic with the red ring around it... I'm not sure if it is still in one piece though in my garage somewhere

 

[ollietheox]

Great work.  Thanks for that.  Will have a crack at it the weekend as the weather is meant to be crap. 

[MrPug]

Just a note that the picture is of the S50 box. I'm pretty sure the S28 reverse gear setup is identical, but you will find you have a few less pieces in your box, like no metal brace, a bearing or two etc etc.

[ollietheox]

Did notice you had a few extra pieces and assumed it was the difference between S28 and S50.  If all else fails, may have to source a S50 box

[jari]

if you want an S28 gearbox I might have one spare - a new one out of a RTR S28. Brushless conversion is on the cards and I already have the S50 box to replace the s28 one.

[ollietheox]

Depends on how much we are talking about?