New guy- RACO Jack Rabbit Restoration and Issues

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jtherrien
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New guy- RACO Jack Rabbit Restoration and Issues

Post by jtherrien »

Hey guys-

I'm new to quarterscalelegends.com and the 1/4 scale hobby. I just purchased a RACO Jack Rabbit because I thought that 2-stroke would be way easier than nitro. And honestly, they are way cooler than the average Baja.

The car looks pretty good minus a few flaws. The plastic shock tower in the front seems a bit bent to one side, and I think I might need to buy a new one (if I can find one). Also, there's a squeaking sound coming from what seems to be the clutch inside of the coupling behind the engine. I'm afraid to oil the area b/c its a clutch- any suggestions as to what I should do? The squeaking is only momentary- it occurs as the engine rotates. The control arms also squeak, so I plan to oil those.

The buggy is (was) "RTR" with a standard TRAXXAS 27mhz tx and a rebuilt Zenoah which starts usually on the first or second pull. So far, I've only done cosmetic work on the aluminum parts w/ some Mother's mags& aluminum polish- it looks great. Came w/ iNTEGY shocks front & rear. I plan to add a 2.4ghz tx/rx system and a fail safe to the 3rd channel. I'm replacing the old servos w/ metal gear Futaba s3306mg's.

Any suggestions? solutions to the squeaks? Your help and patience is greatly appreciated.
Thanks, Jared
Al Gibson (QSL)
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Re: New guy- RACO Jack Rabbit Restoration and Issues

Post by Al Gibson (QSL) »

jtherrien

Welcome to QSL, i hope that you enjoy the site. There are a bunch of people on this site that know everything there is to know about your car. I am sure help will arrive shortly. Thanks for joining QSL, Al Gibson
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vwguru75
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Re: New guy- RACO Jack Rabbit Restoration and Issues

Post by vwguru75 »

Welcome to the large scale world!

I would like to see you pull the motor and inspect the clutch for wear. It's possible it just needs a clutch but the other possibility is it needs a trans input bearing. More than likely it's the clutch. Should be cheap enough to obtain a new one. Ebay has a ton of clutches for Zenoahs.

Someone had posted a source of new front suspension towers recently. I have not used the supplier but perhaps you can reach out to them and let us all know how they are.
http://www.gpplastics.com/Raco.html


Post some pictures of your car when you can so we can see what you have.

Here's a couple of action shots of one of my Rabbits de-thatching a lawn.
Image

Image
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jtherrien
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Re: New guy- RACO Jack Rabbit Restoration and Issues: Pics

Post by jtherrien »

Here are some pics. As you can see in the second pic, the front suspension is bent to one side. From the looks of it, I don't think the chassis is bent. I'll take the plastics off soon to see if they are the problem- if so, I'll try out that plastics site. Thanks for the source.

I took off the engine and I have some pics below of the clutch and the gear case coupling that it slides into. The insides look ok, but on the outside, not so much. I see some remnants of grease on the outside of the clutch but it looks pretty dry. Should that be oiled, or is it just gunk built up? Please pardon my inexperience. If more pictures would help let me know. Thanks
20140322_141145.jpg
bent shock towers visible
bent shock towers visible
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20140323_142729.jpg
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PTModIT
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Re: New guy- RACO Jack Rabbit Restoration and Issues

Post by PTModIT »

Looking at the last pic you posted it looks like the gearbox around the clutch drum has melted.( Its a 1/2" lip around the clutch drum.) The gearbox should slide out of the hole in the shock tower.Pull the gearbox out and post a pic of it. The blackish residue on the aluminum casing where the clutch shoe is normal.Its the dust from the clutch shoe.
PTModIT
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Re: New guy- RACO Jack Rabbit Restoration and Issues

Post by PTModIT »

The lip should be round and smooth like in this pic. Image
PTModIT
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Re: New guy- RACO Jack Rabbit Restoration and Issues

Post by PTModIT »

Those adjustable rod end linkage on the rear swing arms should be removed if you go off roading. Jac-Rabbits did not have them. The Raco Super Mod did. Same car but shorter shocks.That car was used for flat track and pavement racing.I can't tell what length the shocks are.
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vwguru75
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Re: New guy- RACO Jack Rabbit Restoration and Issues

Post by vwguru75 »

It looks to me that the spring is worn and not holding the shoes tight against their hub. This will cause the shoes to drag on the inside of the clutch bell. This creates excessive heat and will melt the housing and possibly cooked the bearing behind the clutch drum inside the trans.

Just what I can see from the pictures you posted.

The other issue of the bent front shock tower is that it is deformed from a crash. It also looks like it was over tightened and the tops are deformed from it. Replacing the towers should rectify this and possibly adding supports from the top shock mount bolts down to the chassis will keep things in place and stiffen the whole setup. If you poke around looking for pictures of Rabbits you'll see the supports I'm talking about. You can make them or try and find them. Making them would be a lot faster. :lol:

One I had a long time ago, my second quarter scale car.
Image
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jtherrien
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Re: New guy- RACO Jack Rabbit Restoration and Issues

Post by jtherrien »

PTModIT-

Below are some pics of the trans/gear case. The lip looks like it's intact, I think it was just loose in the picture and not fully coming through the shock tower hole. Thanks for the tip w/ the shocks. The guy I bought it from put iNTEGYs that are much too big. The rear shock tower was installed with about an inch of washers underneath it to make the setup tall enough :lol: The tower is somewhat unstable now; this might be the reason for the engine's vibration/jerking movement while running... and possibly the squeaking? The rear end is extremely stiff as a result, and the springs actually rub on the plastic control arms in the front.

I think I'll clean the brakes and grease the dog bones while I have everything disassembled. The car is completely dismantled down to the bare chassis at this point.

vwguru-

I can't tell how well the spring is doing inside the clutch. It moves a bit (probably tolerance?) but it's not loose. About the trans bearing melting- would it help if I took off the clutch drum to see inside? The squeaking seemed to be coming from the clutch but only when it was inside the clutch bell. The gears in the gearbox seem to be moving freely, minus some crunching from dirt on the dog bones.

I'll check out the plastics site to get the front shock towers. Replacing them and straitening them out might help with the front springs rubbing.
gearbox lip
gearbox lip
20140327_172225.jpg
20140327_172208.jpg
20140327_172253.jpg
discovered that the rear of the chassis also has some damage.
discovered that the rear of the chassis also has some damage.
PTModIT
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Re: New guy- RACO Jack Rabbit Restoration and Issues

Post by PTModIT »

Do you feel ambitious.You should take the gearbox apart to see what it looks like in there. You never know what somebody else did when it come to maintenance. Take a pic of the gearbox with the half case off, If you don't you could put the gears in wrong and the car will run backwards. If he put extra washers under the rear shock tower did he put extra washers under the engine shroud?(The 2 bolts that attach the engine to the chassis.) The gearbox, shock tower and engine when bolted to the chassis should sit flat, Not angled. I noticed he used washers under the shock tower. There should be spacers about 1/2" I think, I would have to measure mine to give you the exact thickness. See if there is any movement with the clutch drum. There should be no side to side movement. Meaning there is play where the bearing sits behind the drum.
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vwguru75
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Re: New guy- RACO Jack Rabbit Restoration and Issues

Post by vwguru75 »

Clutch spring needs replacing......I can one shoe not touching the rest. You can buy springs on eBay cheap. I don't recommend going with the high RPM spring maybe 6-7,000 rpm or so.
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PTModIT
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Re: New guy- RACO Jack Rabbit Restoration and Issues

Post by PTModIT »

Yes I see that to. Both shoes should be touching on both sides where the bolts are. Actually, I would buy new shoes and spring. those shoes have been known to break where that slot is in the shoe. I had it happen to me.
jtherrien
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Re: New guy- RACO Jack Rabbit Restoration and Issues

Post by jtherrien »

There are no bolts holding the engine to the chassis. All of the engine's weight is being held by the bolts of the clutch coupling, which go through the shock tower and then bolt into the gear case. Also, nothing is bolting the the gear case down- currently, it's only screwed into the shock tower. Basically, everything is hung off of the shock tower, causing the whole setup to be loose and causing the engine to move /bob up and down when being revved up.

Could the looseness of the clutch shoes be the cause of the squeaking? I'm looking on eBay for replacements.

I'll take the gear case apart and post pics soon.
PTModIT
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Re: New guy- RACO Jack Rabbit Restoration and Issues

Post by PTModIT »

There should be 2 metric screws at the bottom of shroud under the pull start.I hope the mounts are not broken.
jtherrien
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Re: New guy- RACO Jack Rabbit Restoration and Issues

Post by jtherrien »

Those mounts seem to have been broken off- take a look at the large holes in the plastic. Any suggestions for how I can repair that? The clutch bell moves back and forth a little bit (+/- 1mm) but I suspect that is for tolerance.

I took a shot of taking apart the gear case. I couldn't get the front half off- the seam looks like its fused, or maybe just really tight- I don't think I should force it. From the outside looking in, everything looks well greased. Take a look at the rear gears.

What is wrong with the clutch spring & shoes rubbing? Could they be the squeaking issue? I'm trying to keep the budget as low as possible and would like to avoid an necessary clutch purchase. If it helps at all, this just came to mind, in a lot of YouTube videos, Jac-Rabbits idle without moving. Mine moves slowly when idling unless the brake is applied. Is it time for a new clutch (shoes & spring)?
Broken mounts
Broken mounts
rear gears
rear gears
Rear gears
Rear gears
Inside of the rear case
Inside of the rear case
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