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qatmix

1986 bigwig restoration and help needed (A Thread)

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Hi All,


I am currently restoring a vintage Bigwig I recently picked up. It was filthy.. I mean proper, proper dirty and covered in grease. I have eventually cleaned it all and started today to rebuild the gearboxes. 

They all went together well, and I swapped out the few bushings for bearings.  The rear gearbox feels  fine.  The differentials spin if I hold the spur gear and the prop makes rear wheels spin.

However the front gearbox does not work properly. When i spin the prop shaft the front wheels turn. However if I grab an outdrive  to test the differential, the prop still spins but the front outdrives do not spin at all. It is like I have mounted a ball diff and it is really loose, however this is obviously a gear diff, so I just have no idea what is wrong.. Anyone got a clue? I've checked the manual and I just cannot see anything obvious. 

I have a long way to go, so this thread might take some time.. I want to ultimately make this my fun retro runner / racer. It has all the quirks of the Boomerang (Which I used to race back in the day), but has some even more interesting features such as the rack and pinion steering, and obviously it has four shocks. 

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Help! :) 

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Have you replaced any parts in the front gearbox? The rere have a different case with space for large e clips on the outdrives. These don't fit thd original cases that used tiny wire c clips on the out drives. I ran into this on a vintage boomerang 

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Nope, it’s all still the original components. (Just wiped out the excessive grease). 
 

It seems inconsistent, sometimes it actually feels ok. Other times it’s floppy / no drive. 

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50 minutes ago, qatmix said:

Nope, it’s all still the original components. (Just wiped out the excessive grease). 
 

It seems inconsistent, sometimes it actually feels ok. Other times it’s floppy / no drive. 

Is the 2mm diameter pin still in place that fits inside the outdrives / drive cups?

 

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Yup, It’s still there. Although at the moment the gearbox isn’t installed in the chassis. I’m testing them on the bench with a screwdriver in the prop. 

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Have you checked the splines on the drive cups and the insides of the bevel gears are ok ? The bevel gears are made from Chineseium and are very soft, it's possible, although unlikely, that the spines inside the gears have been shredded...

 

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Yep again it all seems pretty good. Stripped it down, and rebuilt it again before work. I noticed one of the small bevel gears still has some dirt in it.. so I gave that a clean. I assembled it and it had drive.. it wasn't always diffing out both sides.. but then I spun the prop a bit more and it sort of clicked into place and now it seems fine.. I can only assume some of the gears were still binding a bit from the hardened grease that I tried to strip off

 

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Funny. I’m having front gear box issues with my boomerang. Out of all 6 cars I retained from the 80’s that’s the only one with gearbox issues. I found my culprit. And I may have extra parts for you. I’m going to try and tackle me issues tonight now I just got the last parts I was waiting on from the UK in todays mail. I’ll post up more later to see if it’s any help. 

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On 2/28/2022 at 5:26 AM, qatmix said:

... swapped out the few bushings for bearings....

beware all used Ts which spent their previous lives running bushings

Bushings would've worn grooves into the shafts they spin on; your new bearings could be spinning on the worndown shafts & the gear mesh could be outta whack.

Worn bushings at the outdrives also do some wierd wear patterns on the potmetal bevel gears.

 

In the original hotshot gearboxes, we'd add a 850 bushing (yeah bronze bushing, you'd have lots spare?) on the outdrive shaft before it stabs into the 1150 bearing. Helps support it somewhat, keeps chunky dirt out of the 1150 too.

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How do you remove the C-Clips without breaking them? they are so small.. will a flat head screwdriver do it?

I've been cleaning the rest of the parts today.. found a few horrors. I aim to get this running without buying loads of new parts, although I do need a drive shaft and the two prop joints.  Would a TT02 prop shaft and cups fit? I seem to have found some people saying they do.. Otherwise is there a good alternative to the kit piano wire?
 

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6 minutes ago, qatmix said:

How do you remove the C-Clips without breaking them? they are so small.. will a flat head screwdriver do it?

I've been cleaning the rest of the parts today.. found a few horrors. I aim to get this running without buying loads of new parts, although I do need a drive shaft and the two prop joints.  Would a TT02 prop shaft and cups fit? I seem to have found some people saying they do.. Otherwise is there a good alternative to the kit piano wire?
 

Don't know if the TT02 parts fit, but the Super Hotshot aluminium prop and matching cups are the hop up.

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922876312_image0(1).thumb.jpeg.ac1035b4ce5cc9e7c9bc2f4d30c3efaa.jpeg
EEK! This part of the tub has snapped, any idea what might be a good repair?  It seems that Bigwig chassis are not available anymore, so ideally I want to try find a solution here.


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Also one of the front gearbox halves actually has a crack.. I will try to bond that as I don't want to buy a whole new gearbox as I think I might need to change the outdrives (They now take a thicker E clip). 
 

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I use 2 small flathead jewellers screwdrivers to get the c clips off. Hold the clip steady with screw driver in left hand, then apply pressure to the other end of the clip with screwdriver in right hand, whilst simultaneously trying to stop it flying across the room into oblivion by using a spare finger on my left hand to try and  trap it as it comes off the drive cup.

If it was any more fiddly, it would have qualified for use in a schumacher car...... ;)

 

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Sounds complex, but let’s hope the glue holds it together.

The big issue is that tub.. I am a little stumped on how to sort it. I might have to clue the shock tower to the tub, which is a bit drastic.

The other option is to make some sort of bracket.. It’s just a shame that all the bigwig tubs seem to have sold out. 

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13 hours ago, MadInventor said:

whilst simultaneously trying to stop it flying across the room into oblivion

work inside a big clear plastic bag ;)

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Unable to find a bigwig chassis tub, so I bought some Milliput Black and decided to fashion a repair.

152121DD-5449-4775-A238-0AC93F95E727.thumb.jpeg.bcc68b8f7de4cb60e791bc86f726c6b5.jpeg

 

It actually worked ok. I’m really surprised how well it has bonded.  It will at least allow me to start rebuilding it and I can swap in a chassis when I find one.


98F9A527-3D03-4874-AB84-7E14E6D5C7E4.thumb.jpeg.9b02283600b19aec9672c3b29c2fbec6.jpeg
I also found more horrors! 😱I removed some 4mm wood screws from this when disassembling the Bigwig.  The previous owner had probably tired to use them to hold the gearbox on the broken chassis. The issue is that the screw holes are as large as the head of a std m3 screw, so it just wobbles around :(

hopefully someone will have a spare as they seem to come with the boomerang sprue so there might be a few boomer guys with these spare.

 

 

 

 

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Been a bit slow on the rebuild, but just fired up the technigold. Gave it a quick inspection and it’s in great condition,  brushes and comm look fine. Just cleaned it and added some lubricant. 
 

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I just connected it to a lipo and it span merrily away.  I’m not one for older motors, but I do have a soft spot for these. They were just so out of reach when I was a boy. 

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On 3/6/2022 at 11:05 AM, qatmix said:

Unable to find a bigwig chassis tub, so I bought some Milliput Black and decided to fashion a repair.

152121DD-5449-4775-A238-0AC93F95E727.thumb.jpeg.bcc68b8f7de4cb60e791bc86f726c6b5.jpeg

 

It actually worked ok. I’m really surprised how well it has bonded.  It will at least allow me to start rebuilding it and I can swap in a chassis when I find one.


98F9A527-3D03-4874-AB84-7E14E6D5C7E4.thumb.jpeg.9b02283600b19aec9672c3b29c2fbec6.jpeg
I also found more horrors! 😱I removed some 4mm wood screws from this when disassembling the Bigwig.  The previous owner had probably tired to use them to hold the gearbox on the broken chassis. The issue is that the screw holes are as large as the head of a std m3 screw, so it just wobbles around :(

hopefully someone will have a spare as they seem to come with the boomerang sprue so there might be a few boomer guys with these spare.

 

 

 

 

I got a set from Tamico in Germany, along with the rubber boots for the rack and pinion steering 

 

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Unfortunately they will not ship unless the order is over 160 euro :( 

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