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GST revs but BARELY moves? HELP!

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GST revs but BARELY moves? HELP!

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Old 04-22-2007 | 01:04 PM
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Default GST revs but BARELY moves? HELP!

Yah soi still haven't ran it since it took a swim in the water hole but everything is back together, so i took it out tried tuning it and then i had that rear axle yoke loosen up on me and i had THOUGHT that was the problem BUT it wasen't, took it back outside yesterday and still the same thing, it revs but dosen't move. Anyone know what might be going on? Could it be maybe i blew both differentials? Maybe the transmission is screwed? Anyone have any idea before i start ripping it apart in anger?
Old 04-22-2007 | 03:19 PM
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Default RE: GST revs but BARELY moves? HELP!

I'm not sure what the problem could be. Check your brake linkage and also check your servo for the reverse and make sure its set correctly, its sounds like it is stuck in nuetrual. Also check your gear mesh and the grub screws on the driveshafts, theese are the simple things I would check first before pulling things apart. good luck!
Old 04-22-2007 | 04:45 PM
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Default RE: GST revs but BARELY moves? HELP!

Where is the grub screw and what does it do exactly?
Old 04-22-2007 | 05:21 PM
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Default RE: GST revs but BARELY moves? HELP!

If you look underneath the truck you will see the drive shafts that go to the transmission. At the end of each driveshaft is a drive cup. Theese drive cups spin the driveshaft which spin the diff. The drive cup are held in place by small tiny setscrews also called grubscrews.If theese are loose, they will spin but supply no power the the wheels. I suggest that you locktite them in place because they come loose very easily.
Old 04-22-2007 | 07:44 PM
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Default RE: GST revs but BARELY moves? HELP!

got it. I'll check them out and see if that has anything to do with it?
Old 04-23-2007 | 06:53 AM
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Default RE: GST revs but BARELY moves? HELP!

Hey JUCD VPR,

After having quickly checked all the above things, can you see movement in the following places? (Put her on a block of wood or a stand or something simmilar, when engine is running).

1/. When you rev your engine, does the flywheel turn? If not why?
2/. Does the clutch engage, & turn the pinion gears? If not why?
3/. Do your spur gears turn? Firstly, 1st gear? If not why?
4/. Does the other side of your tranny's 1st gear shaft turn when its spurs turn? If not why? (see where I'm going with this?)
5/. Does the other shaft in your center tranny also turn? (3rd speed shift assembly). If not why?
6/. Does the output of your center tranny turn? (output brake drive cups). If not why?
7/. Does the input drive cups to your diffs turn? If not why?
8/. Does the output shafts from your diffs turn? If not why?
9/. Is there a solid connection, between your axles & your wheels? therefore do your wheels turn? If not why?

I Guess what I am saying is, follow your drive line all the way through, to find where the driving force stops. Then you will know where the failure is.

Hope this helps, .46NitroAddict [>:]
Old 04-24-2007 | 10:27 AM
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Default RE: GST revs but BARELY moves? HELP!

Thanks for the help so far guys.

So i was playing around and checking stuff out and the rear diff seemed to be acting strang so i figured i broke something in there, took it completely apart and yup, BROKEN the differential bevel gear on the right rear, so i replaced the whole thing with the spare diff i had.

NOW here is my question, IF ONLY the right rear diff was broken the truck would still go correct? It would just be front wheel drive though right? BUT the truck WAS NOT moving so i'm assuming something in the front diff is broken also, I was turning the front axles and it SEEMS to be ok but i was just asking before i spend the time ripping the whole front end apart. I'm THINKING the front diff is broken also, maybe a bevel gear but i guess i won;t know until i take it apart, just wondering what you guys though. Why in the world did i break a diff bevel gear yoke anyway? Think this is covered by CEN? Should i e-mail or call them and ask for a replacement part?

So what do you think call CEN and ask for another diff bevel gear?
Take apart the front diff?

I wasen't even bashing when i broke these i was tuning the high end needle, hmm?
Old 04-24-2007 | 09:11 PM
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Default RE: GST revs but BARELY moves? HELP!

ORIGINAL: JUCD VPR

......NOW here is my question, IF ONLY the right rear diff was broken the truck would still go correct? It would just be front wheel drive though right? BUT the truck WAS NOT moving so i'm assuming something in the front diff is broken also, I was turning the front axles and it SEEMS to be ok but i was just asking before i spend the time ripping the whole front end apart....... Think this is covered by CEN? Should i e-mail or call them and ask for a replacement part?

So what do you think call CEN and ask for another diff bevel gear?
Take apart the front diff?
Hey JUCD VPR,

Ok, first question, is your center diff locked (is the lock block fitted)?

IF the answer is NO, then you could reasonably expect the truck to barely move! Because your driveline will take the path of least resistance - to the rear diff. Doesn't mean nothing else is broken, just that it is possible!

If the answer is YES, then you definately have another problem. Because the lock block will cause an equal amount of driving force (rotation) to be delivered from the center diff to both the front & rear diffs (it could be a front, rear wheel, or allwheel drive - depending on which diff/s you have connected).
So what are the answers to my previously posted questions? You can still do it, with the motor not running (you will only be testing 1st gear) but it will still show you where your problem is - just turn you clutch bell by hand (standing at the front of your truck looking into your motor the clutch bell turns anti-clockwise). As long as the problem is not in 2nd or 3rd gear! If that tests fine, then lock your 2nd gear into engagement, you can then check its operation. If that is fine, then your problem must be in 3rd gear. You may want to do this with the truck on the ground (up against something), so that the wheels have some resistance to act on.

As far as warranty, is it within the 60 day period?
Yes, then go back to place of purchase, & try!
If no, then no!

Regards, .46NitroAddict [>:]
Old 04-24-2007 | 09:17 PM
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Default RE: GST revs but BARELY moves? HELP!

I seariously doubt that the front diff is also broke. These trucks have a center diff. All power goes to the least traction wheel. If the rear diff was broke 99.9% of the power went there (path of least resistance). You can easily test it by hand if it is OK.

If you have to break things open try 500k diff fluid in the center diff. More resistance means that you will get less unloading in the front.
Old 04-25-2007 | 05:31 AM
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Default RE: GST revs but BARELY moves? HELP!

Haha i have no idea if the center diff is locked, i haven't messed with it since i bought the truck. So if it comes locked from the factory or not i have no idea? How do i lock and unlock the center diff?

I believe it's under 60 days that i've had the truck, can i just call Cen and ask for a replacement part or do i need to find out who i purchased it from and ask them? I bought mine new off e-bay, i assume these people are dealers since they sell tons of them.

Also with the gears? I have no idea how to check 2nd gear or what not. I don't even know if the truck has went into 3rd gear or not, i couldn't really ever hear it but it was fast so i just assumed it did?
So when you say things like "lock your 2nd gear into engagement" i have no idea how to do that?
Old 04-25-2007 | 09:05 AM
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Default RE: GST revs but BARELY moves? HELP!

Hi JUCD VPR,

Ok, this is going to be very short, sorry - Plane to catch (will be back on 1st may).

CEN Genesis / Nemesis / GST all come from factory without lock block fitted to their center diff. They instead have a grease / oil around 100k wt in all 3 diffs.
So it is conceivable that you have infact fixed your only problem. Because as I previously stated & air1kdf confirmed, when the center diff is unlocked, 99% of all driving force will go out the path of least resistance. ie. your broken drive. (not to say this is your only problem, but most likely it is).

Warranty claims in the first place should go through your seller, so give him a call, & get that claim under way! Failling his action, you could try CEN Racing - contact section of their [link=http://www.cenracing.com/main.html]web site[/link]

Once you have fitted your new diff, give her a quick inspection, even using my previously posted check list (by hand for 1st gear will do), & if she checks out ok, take her outside & give her a gentle run. You will soon know how you went!

Good Luck, .46NitroAddict[>:]
Old 04-25-2007 | 09:58 AM
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Default RE: GST revs but BARELY moves? HELP!

Cool thanks for the info.
It's all back together so tomorrow i'll take her out for a spin.
SHOULD i lock the center diff now? OR should i wait and order some diff oil and lock it then. How do i lock it? I only bash no racing.
Old 06-16-2007 | 11:08 PM
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Default RE: GST revs but BARELY moves? HELP!

tighten ur spur gear
Old 06-18-2007 | 06:21 PM
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Default RE: GST revs but BARELY moves? HELP!

The most comon reason would be a scheared diff cup out drive... check the action of your differential and make sure that the front and rear diff spin in the same fashion. For further assistance dont forget to contact our main tech guy [email protected]
Old 06-18-2007 | 09:11 PM
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Default RE: GST revs but BARELY moves? HELP!

Check your set screws at the front and rear diff input drive cup. Those are always loose.
Old 06-18-2007 | 09:42 PM
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Default RE: GST revs but BARELY moves? HELP!

LOL Do you guys realize that this topic is 2 months old. I thing VPR fixed his problem.
Old 06-18-2007 | 10:11 PM
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Default RE: GST revs but BARELY moves? HELP!

LOL DARKFIRE!!! LMAO rollin' hard!! you are right!!! See how digging up some old chit gets us wound up!!! Funny stuff!!!


hhaaahhhaaa dogman's laughin' hard as I walk off into the distance mumbling "how funny"
Old 06-20-2007 | 01:04 PM
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Default RE: GST revs but BARELY moves? HELP!

lol
Old 06-27-2007 | 09:57 PM
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Default RE: GST revs but BARELY moves? HELP!


ORIGINAL: .46NitroAddict

Hey JUCD VPR,

After having quickly checked all the above things, can you see movement in the following places? (Put her on a block of wood or a stand or something simmilar, when engine is running).

1/. When you rev your engine, does the flywheel turn? If not why?
2/. Does the clutch engage, & turn the pinion gears? If not why?
3/. Do your spur gears turn? Firstly, 1st gear? If not why?
I can answer yes to all of these, where do I go from here? I am a noobie so as much step by step as possible would be great.
Old 06-29-2007 | 11:46 AM
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Default RE: GST revs but BARELY moves? HELP!


ORIGINAL: jarlin


...............I can answer yes to all of these, where do I go from here? I am a noobie so as much step by step as possible would be great.
Hi jarlin,

Ok if you can answer yes to those, what about all my other questions in post #6?

Regards, .46NitroAddict[>:]
Old 06-29-2007 | 01:33 PM
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Default RE: GST revs but BARELY moves? HELP!

I have found the problem. It is the pin and barrel that holds the front drive shaft to the center diff. Must have broke it off or lost the e clips
Old 06-29-2007 | 04:30 PM
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Default RE: GST revs but BARELY moves? HELP!

Just happened to my buddy at my track also. I think this might have to be an upgrade part soon lol...

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