Problems With Ta01 Gear Box Off Road

[pikachoo75 0]

yeah i know! it is confusing!

the 5 hole modified is listed as ta01 and termed "modified" as it allows 18-22 teeth pinions on the standard spur.this modification on the motor mount allows bigger pinions on the standard spur for higher top speed.(tho if you have larger than touring type diameter wheels,such as buggy wheels,this can prove to be a less useful ratio)the makers must assume that ta01 versions such as manta ray/top force USUALLY dont accept the speed tuned spur gears.

the 6 hole standard mount is quoted as ta02 as this type pretty much always feature the red "skyline" rear gearcase that is compatible with Tamiya's speed tuned gear set.

the speed tune gears are smaller spurs to allow bigger pinions for higher top speed with touring car wheels rather than larger diameter buggy wheels.

Tamiya's speed tuned gears come with an instruction sheet that explains that your ta01/02 manta ray or equiv rear gearbox has to have a certain teardrop shaped aperture were the motor fits.the red coloured gearcase is shaped to suit,but some of the early black coloured gearcases have a circular aperture,so the motor wont allow itself to move closer to allow the bigger pinions to reach the smaller spurs.

i think the makers are playing it safe by assuming that ta01 is most likely to be grouped with the black coloured gearcases such as buggies and the ta02 is the red gear cases tho it does have a "big wheel" variant in the trophie trucks.

basicly Tamiya say that a buggy or big wheel variant should use gear ratios within the "standard" mounts range and smaller wheeled touring/rally types can benifit from gear ratios that a "modified" mount or speed tuned gear set provide.

what gpm provide their "modified" mount for is to allow bigger pinions for buggys(torquey motor ,bigger pinion in something like a top force).for the non racing/basher this high gear ratio isnt realy useful as it might go faster in a straight line but the accel/run time isnt that good.i dont know if gpm are aware of Tamiya's gearbox difference tho.

good greif...i just read this back to myself! to think that i said the mount idea was to simplify things!

[nckmat 0]

So I have just rebuilt the gearbox again, after racing on Sunday using the GPM mount, and I think I have cracked it this time; it's the gap between the GPM mount and the gear case that is causing most of the trouble. Photos to follow shortly....

[nckmat 0]

OK so here are some of the images. First how the plastic mount fits

[pikachoo75 0]

this is the 5 hole blue gpm modified mount in the red skyline type gearcase.

times must be hard when Stevie Wonder has to moonlight at gpm to make ends meet!

[attachment=2844:tc3.jpg.

[DI Joe 0]

Sorry - Duplicate post...

[DI Joe 0]

All,

Very interesting, the last couple of posts. I have had motor mounts by GPM for some time, and have sold them for the last year or so and had not encountered this problem before. The mounts I usually sell (to clear up the confusion) are the 'modified motor mounts' which are fot 18-22tooth pinions. These fit all DF-01 gearbox equipped cars. GPM actually make two mounts, the standard being more or less identical to the plastic one and being for 16t pinions up. They very rarely have these avilable.

In terms of GPM's quality, I understood from people that have used them for years that it was there early manufactured parts that were slightly dodgy, and that from 2005 onwards they had re-tooled increasing there quality. I will pass this thread onto GPM to see if they will comment directly. How many are there then with this problem?

Cheers

Richard Tomkins

X3 Racing

[nckmat 0]

this is the 5 hole blue gpm modified mount in the red skyline type gearcase.

times must be hard when Stevie Wonder has to moonlight at gpm to make ends meet!

[attachment=2844:tc3.jpg.

No need for me to post the same image. I have now made a gasket out of a business card and that seems to fill the gap well. Not the best solution but it will do until I can find some silicone sheet of the right thickness. Fortunately my wife has a kitchenware store, so I am going to raid some of her silicone bakeware. It's getting the correct thickness that will be hard.

[JT (D1RC) 0]

I run both GPM motor mounts in my TA02's and also use both red and black casings. I did experience one of the mounts sitting proud of the plastic gear case so simply filed down the alloy post(s) until they were flush. However, I suspect the culprit here is gear meshing, or not meshing!

Firstly, ignore the concept of using the right or wrong holes. If you can fathom out the pinion teeth numbers on the GPM mounts fine - use an indelible pen and mark them, but only use them as a guide. Same with the Tamiya pinion positioning tool! Someone above mentioned this, but it's worth repeating:-

'Adjust' the alloy posts (if you have a problem) and trial fit the motor with the gear case lid off and adjust the pinion position until you just have clearance between the end of the pinion and the gear case. Tighten the pinion and refit the motor using what appears to be the correct holes (and the motor plate the correct way up).

Lay the spur gear in place and check the mesh. With this tooth pitch, you should be able to rock the gear too and fro but only just. If it won't move, the mesh is too tight but just the tiniest amount of movement should exist. Simply adjust the mesh by rotating the motor on it's mount by one screw hole. It's a crude method but I guess Tamiya meant it to be idiot proof - and we were all 'idiots' when we built our first car!

The speed tuned gear set provides two extra spurs, one smaller than standard and the other smaller still, this giving a lower ratio and a higher top speed, essential for Touring Cars as the 10:1 'ish final ratio (can't recal the exact figure) is way too high, needs to be around 6.5 for a good 27 - 19turn - not an issue fro the bigger wheeled buggies.

I wouldn't use the Tamiya grease but instead try something like a Triflo teflon light grease. As for the diffs, a ball diff will be more forgiving on the gears as it gives a degree of clutch action. BTW, if you want to use a spool, try this quick, easy and reversible method

http://www.drccentral.com/forum/viewtopic.php?t=10175

I developed this for use on my TA02W Drift chassis, the spool fitting in the rear but it works just the same in the front and can give you better front end grip as you exit corners, slightly less turn in grip so suits more open circuits.

Hope this helps.

[Live Steam Mad 18]

Regarding the meshing of the teeth on gears ;- For the longest time when I was a kid, I thought that gears had to be really tight against each other so that the top of a tooth of one gear pushes against the depression between 2 teeth on the other gear (fully meshed). I finally realised when I was a late teenager that this is completely wrong, and it is the sides of the teeth that push against each other which is important, and that there must be a little play in the mesh (a small amount of clearance) otherwise the wear rate and drag would be astronomical. LOL.

From then on my gearboxes stopped sounding like a chainsaw and started being really smooth hehe

Cheers,

Alistair G.

[pikachoo75 0]

di joe,thanks for the clear up.i guess my mounts must have been proper old stock.as for the poles etc.im going to do whatever is ness to make it all fit as it should.

the beauty of forums like this is we can all share experience with each other

i think this example was so confusing to suss out and sort as unless the gearbox is out of the car its impossible to see whats going on.

jt thanks for the tip on the spur check as this does give peace of mind that all is well before you run the car.

i must admit that having to "tinker" with brand new parts isnt such a big deal,it was trying to find the source of the prob that drove me crazy!

live steam mad,thanks for the mesh info too.my top force made such a high pitched noise...it attracted dogs from miles around!

ive learnt so much from this site,its fantastic.

[nckmat 0]

OK, so I tried the speed tuned gear and the $%^(@ pinion gear slip because of a dodgey grub screw so scrap that idea for a while. Then I fitted the GPM mount with a 22T pinion and fiddled around until I got it a fitting, I can't remember which hole I used but I think it was the 22T hole, but I tried so many combinations I can't quite recall. Anyway, in the end it worked. I also used my business card gasket. I then took it down to our local RC club track and went through a 1500, a 3200 and a 4800 battery before it became too dark to carry on. There wasn't a hint of grinding and I beat my best time from Sunday's race by 2 full laps. Yeehaa!!

I haven't looked inside the gearbox yet but, it sounds fine.

Now I can start putting my Top Force Evo together with confidence. Just as soon as somebody can tell me whether the lower arms on the D tree 0005378, which is the Manta Ray/Top Force/ Blazing Star parts tree, are the same as the lower arms on the D tree 0005429, which is the Top Force Evolution parts tree.

Thanks to all who have given their advice and I will keep adding to my gallery.

[pikachoo75 0]

hi nckmat,im glad its working fine now.

i love it when a plan comes together.

if you have a problem and no one else can help....and if you can find them....maybe you can hire the TC team(que music)

i pity the fool who grinds gears.

(with cigar in the corner of clenched teeth) your blazing star/manta ray/top force/dirt thrasher lower arms are the same,when i changed from plastic shock towers to frp ones the solid top arms became unusable due as said before to the diff in location of fixing point.adj upper arms work.....now stand still till i machine gun round your feet.

also i took a squint at the two different parts trees the mantaray/top force etc one and the top force evo.the arms are the same.the difference lies with the top force evo tree.its a cut down version as not to include the solid upper arms and shock parts you wouldnt have to use.

[Live Steam Mad 18]

Oh yeah, 2 points come to mind, before I forget again...

1) maybe it's obvious but never tighten the grub screw by holding the long end of the Allen Key in your hand. Always hold the short end. Make sure the grub is seated on the flat and not on the round bit LOL. Tighten with Allen Key until Allen Key is twisting NO MORE THAN ABOUT 30 DEGREES. The grub screw and Allen Key are hardened steel but they have not got infinite strength LOL. Holding the long end of the Allen Key in your (strong, mine are weak LOL) hand will possibly result in taking the corners off the Allen Key (ouch), and

2) I ordered the bag with the Top Force Evolution Turnbuckle Tie Rods but when I tried to fit them to the Top Force I found that they are the wrong lengths due to the TF and Evo having different Shock Towers. LOL. DOAH...

Cheers,

Ali G.

[nckmat 0]

Thanks guys,

I think I may need to start a new topic for the for the front tower.

I just got an email from Light Water Models saying: "They are different because of the way the connect to the chassis, one is a plastic tub and the other is plates." sic

Here is a pic of the tower I have purchased:

I know it is different to the one in the Evo manual, but I can't find an original Evo one. The rear looks to be the same as teh Evo.

[djmcnz 755]

Two threads same questions???

[nckmat 0]

Two threads same questions???

Yeah I know it just sort evolved that way. I am moving on to the other one now, as this problem seems to be resolved.