Re- Re Boomerang Possible Weirdness

[B.M.T.]

I'd like anyone who has similar experience with a Boomer, or possibly even the 07 Hotshot to chime in and correct me if I have made a boo boo, please.

So, I build my 08 Boomer to the letter (with the exception of full bearings), with one misgiving. I used the steering knuckles from the main parts tree, assuming that Tamiya included a spare pair, as they do with the drive shaft (there was also a pair of knuckles that looked identical in the small parts box).

Upon completion, it was showing all signs of the front driveshafts being too long. Massive wheel shake at full drop, and steering lock varying on what position the driveshafts were at in their rotation.

So, I check the back of manual and those parts are not used. Handy, as in the instructions, the parts are not quoted with part numbers... I install the two "floaters" from the small parts box. Now it's better, but unless the front suspension is half compressed, there is still bad shake from the front end. The dogbone/driveshafts are tight with no end float. I question if I have mixxed parts up, but the 4 dogbones are the same length and the same number, same to the wheel axles and diff output couplings (and the rear has maybe too much side float).

So, I ask, is this typical of this family of 4WD's, or has something gone burko in either my build or parts supplied?

[wolfdogstinkus]

I could be wrong but I think I remember a recent thread about a Hotshot with the same problem,

He discovered that the driveshafts are slightly different lengths(front and back),

I will try and find it!

E2A: Found it!, maybe not the same problem but hope it helps!

Clicky

[TamTom]

I experienced the same happened to my recent aquired HotShot 2007. It came new built. At full drop of front wishbones the same problem as you described. Then I checked closer and found that the previouse owner mixed up front and rear drive shafts. I changed them and since then it works fine.

[B.M.T.]

Thanks guys!

I'll have a look and see.

What would be the chanced I picked both the wrong ones when I assembled the rear? Pretty good, I think

The annoying thing is, that they are marked as 4 of the same in the manual. Always with Tamiya, I trust the manuals implicitly, because they are never wrong. First time for everything I guess....

I'll post up what I find!.

[TamTom]

The front drive shafts are always shorter than the rear ones. Also they look different to each other. (however, I haven't yet checked with my re-release Boomerang). Hotshot I front drive shafts where notched on both sides towards the dogbone ends. The Hotshot 2007 front drive shats have a bump or call it a raised seam in the middle section to identify what is front or rear shaft.

[HunterZero]

While on the Hot Shot and Super Shot the front dogbones are shorter than the rear ones, this isn't so on the Boomerang. All four are the same length, so no chance of confusion there. The re-re is no different, all dogbones are the same length.

Ther Boomerang uses the TA01 style steering knuckles, which are different to those on the original Hot Shot and Super Shot. You have to use the correct uprights to make sure the wheel axle driveshaft joint pivots in the correct place.

Compare the C1 uprights with the provided pair it says to use, and see if there's any difference in the location of the inside bearing. On inspection of the instructions, the C1 parts appear to be a bit different. Use the knuckles the kit tells you to use as you've done, rather than C1 parts seems the correct way.

- James

[B.M.T.]

Hey all,

I've just had a play, and yes, all four are the same length, and as Hunter said, the same as DF-01.

The non "Bigwig" (as these were on a Bigwig parts tree - thanks for the shock towers, Tamiya ) front hubs (the ones they intend to be used) did make a big difference, but not quite what I'd call fixed or acceptable, as I mentioned before.

Really what it needs is 3mm added to the rear, and 3mm taken from the front dogbones.

Oh well, it'll wear in

I might go looking for a 07 Hotshot dogbone set and have a play.

[HunterZero]

The original Boomerang also came with silver front drive axles, and black rear ones. They look to be the same axle length, but the joint cup is longer on the rear ones. I presume the silver ones up front are shorter to facilitate the steering actuation.

The re-re appears to have all four corners the same, and they look to have the shorter drive cup like the silver front cups on the original.

I wonder if there are any other differences between the re-re front drive shaft cups, compared to the original silver pair?

I don't have a Boomerang so I can't check.

- James

[keithmanx]

The only difference I noticed on the front hubs are that the 'loose in the box' ones have the thread pre tapped top and bottom to make it easier to screw in the pivot balls. the ones on the sprue do not, and I remember as a kid how hard it was to screw the balls in with a poorly fitting screwdriver!

thanks Mr Tamiya!