Bruiser with a "Box full of Neutrals" : (

[wldnas]

I've finally managed to find and fit a 3Ch radio to my Bruiser now that finally works (Thanks for that goto Biggus and Jimbo but just when I think I've finally got it all sorted I find out I now have a big problems with the gear seceltion and this is no fault of the radios [V]

The 4WD gear does still work, that locks in OK but its the other 2 2WD gaers that I'm having trouble with, when I try to engage them I just get that horrible knashing noise as the teeth on the selectors just bounce over each other instead of messing properly and locking the selector rings into place, on looking at the cross section view of the gearbox I can see that there are supposed to be a number of small springs on the main seletor shaft, could it be that if some of these springs were broken then they won't have the pressure to engage the selector rings properly selectors? or is it due to the fact that the teath on the selector have rounded off so no longer able to engage properly?

does any have any Idea what the problem might be, cos I'm not too keen on the idea of taking the gearbox apart to see whats wrong incase I screw it up good and proper.

any advise you ppl can give me would be greatly appreciated

[SJoerD]

Does the gearbox shift properly when you shift 'by hand' in stead of using a servo? [:0]

[wldnas]

Unfortunatly the gear shifting is the same even if I use either the servo or my hands [V]

[robysoldtamiya]

Wldnas,

fist of remember you have a slippery gear and most times it could be wear out. Disconnect your shifting rod from gearbox and try by hands. When you leave the gearbox untouched, it should be in 2nd.

try run your truck (put it down on the ground) this way to see if it works. Next lift your truck, put axales over some blocks so tires will not touch ground and try shifting by hands.

If you press the rod against gearbox you will put 3rd.

If you pull rod you will put 1st and should see front tires turn.

When doing this, apply a little force to rear tires, this to see if little load will stop them ( and you hear the noise from gearbox)

I hope you don't have so much rounded teeth 'cos if something doesn't work it could be the cause.

keep us posted

Roby

[WillyChang]

Before touching anything else, I'd recommend a flush & oilchange.

Take the box & motor out of the car (4 screws, not very hard). Remove all 3 plugs and the motor then shoot in huge amounts of motor spray, keep going until no grunge and grease comes out. Turn the shafts a few times too whilst flushing. (You'll always be amazed how much bronze filings come out.)

If you're lucky its just a sticky selector rod, and this will clear them up. (If you're not-so-lucky, someone might have opened up the box before and reassembled it wrongly. If you're real unlucky the same mis-assembler has lost a few parts in the process. Either case you'll need to disassemble & check, with a copy of the blowup diagram handy.)

To reoil, current practice is to completely fill the box with oil (motor oil is good), then turn the shafts a few times. Then drain out the oil (or else it'll drip out over time anyway - big mess) and the box will run on the residual oil quite happily. Replace plugs and degrease the outside, then reinstall.

Best tip is to always have a copy of the gearbox blowup diagram. Sooner or later you'll not be able to resist opening it up... you know you want to!! []

[WillyChang]

quote:Originally posted by robysoldtamiya

I hope you don't have so much rounded teeth 'cos if something doesn't work it could be the cause.

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Usually worn out gears will show up first on the 4WD mode, as it uses the longest transfer path. If so 4WD-low won't work, but 2WD-medium might work and 2WD-high (straight-through) will keep working.

If someone has taken the box apart before it sounds like one (the rearmost one) of the selector forks was put in the wrong way. Sounds very similar to a 'problem' I had over Easter where I had only 4WD but no 2WD modes. (ok ok I was watching TV whilst trying to stuff all the bits back into the box [|)])

[wldnas]

Thanks for the advise so far guys, but to be brutally honest, I don't think a "no load" test run or oil change is going to fix this, the problem has manifested it self after I did a third radio change on the truck, when I first got it, it was only fitted with a two channel and the transmission was running quite hapily in second, I took that radio out to try and fit a ramshackle 3Ch system using an old Futaba 35Mhz FM 4 Channel Tx fitted with 40Meg crystals working a Hitec single conversion 40Mhz RX to which 3 servos were fitted, a Futaba S3001, FP-S148 and a Hi-tec 3003. the S148 had a stripped gear and was very notchy so I fitted that to the Speedo, anyway I could not get the radio to operate properly, its was VERY interfearnce prone, just moving my hands around the chassis caused it to convulse violently, and during this time the speedo was wacking the truck in forwards and reverse while the shifter was griding all the gears to swarf, I gave up on that radio and waited till I got hold of an old Futaba Medallion 3Ch AM and matched it with a equally vintage 4Ch A type AM reciver and some servos, this radio functions perfectly and this is the set currently fitted, but as I said I've lost both the 2WD gear, they just won't engage instead they just grate away endlessly []

It's my opinion that during the spasmodic funtioning of the hybrid FM Radio set I was using the radio was try to shif while the transmission was in motion and had rounded off the main selector gears of the Hi & Low 2WD gears, I did have a thought that perhaps one or two of the seletor springs have broke through the riggerous jarring they would have had, but I guess nothing short of a complete strip and rebuild of the transmission will give the final answer.

I may try your Oil change method WillyChang but I'm not that hopefull of success [V]

If the worst comes to worst, where might I download a detailed exploded diagram of the Transmissions inner workings?

[raemin]

quote:Originally posted by wldnas

Thanks for the advise so far guys, but to be brutally honest, I don't think a "no load" test run or oil change is going to fix this, the problem has manifested it self after I did a third radio change on the truck, when I first got it, it was only fitted with a two channel and the transmission was running quite hapily in second

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In that case I assume the gearbox was locked in second position : by not using the other speeds, some oxydation may hava alterated the internal axles. The first time you shifted the gears, those rusty axles went blocked. I had a similar problem with a real car : the lady never used it at full throtle and hence the first time I tried the carm on the openroad, the carburator just got locked at max speed!!! with some standard wd40 this should disapear easily.

[JesterRace]

Just pop the trans apart and look at all the gears. Clean and re-lube everything, it's not that hard...I've done it many times. It just looks hard, just be patient when taking it apart and don't let anything fly off.

[WillyChang]

With your radio botching the gearchange... there's a good chance that the frontmost gearring has blunted the teeth on the nylon gear (yup, the clicker gear).

Take off the motor and the 1st segment and that'll let you remove the nylon gear. Don't worry there's nothing to fly out here.

[poulpit]

If the worst comes to worst, where might I download a detailed exploded diagram of the Transmissions inner workings?

Hi WLDNAS,

You can find an explosed view on the great website from Roby's old Tamiya.

http://oldtamiya.interfree.it/ click on explosed view and than, 0000!

or on this great website too! with pictures.[](.pdf need acrobat reader!)

http://kope.com/bruiser/TrannySvcManual.pdf

[)]