KiwiJay

Hey guys, I'm trying to get a 1/8th scale nitro buggy running that I bought a while back.
The car is a Thunder Tiger EB4 S2.5 PRO buggy, and while the car presents well, it has a issue with the centre diff.
I have dismantled the diff to find it looks like it was run dry, with the gears melting into their respective mounts, 3 of the smaller gears spin, but one is seized into its position.
My question is, can I just lock the diff if I can't get the gearing to mesh properly.
I've read a hot glue gun can do the job fine.
Will it have any adverse affect to its driveability (not racing it, just bashing on the road or gravel)?
And will it stress other parts of the car to much?
Appreciate any help or advice given.
Cheers.
Jay.

Maxximize

I don't have much experience with center diffs, but a great old school mod for locking diffs is to cram silly putty into it, and reassemble. That way if it causes problems, it's easily reversible. I have heard of many people converting center diffs in various cars/trucks to solid shaft, so I don't think it would cause issues with breakage, but it could make the buggy harder to steer under power. It does seem to give better straight line power from what I've seen, though. Personally, I'd rebuild the diff anyways or replace it though.

KiwiJay

Thanks for the input maximise, I do intend on replacing it, but as I'd like to take it out for a bash tomorrow at the local 1/8th track, I really just looking for a temporary fix till I can get what I need ordered.

JonnyW

iTrader: (5)

If one gear is seized up then it is locked. In a proper diff all the gears are messed together. So one turns they all turn. And in your case the opposite. It will be a handful to drive locked up. You may be ok doing for awhile once. But you may do further damage to the rest of your drivetrain. Diff gears and cases are pretty cheap. Entire diffs can be had new for $20 or so.

Maxximize

I hear ya there. Half this hobby is temporary fixes it seems Anything to run until the parts needed arrive or ya got time to go to the LHS. Anyways if it's a junk diff you could just use hot glue or thick CA glue to fill it. JB Weld works well, too. For a good diff, silly putty or the thickest silicone diff oil you can buy.

Cday

iTrader: (7)

Get a new diff for sure. There definitely will be different driving characteristics to a locked center diff and one that isnt locked. Just lock it until you can buy a new one for now.

KiwiJay

That was the plan, turned out its smashed up one of the centre diff mounts where the bearing sits (and brakes are mounted), so even locked it was only a matter of time before I destroyed it completely.
Thankfully the EB4 buggy appears to have pretty good support for parts and such still, so I'll get upgraded mounting posts and diff I reckon.
Thanks for the input guys.

KiwiJay

Just a bit of an update, I found that with my Thunder Tiger EB4 S2.5 Pro that you can't just buy a centre diff, they sell it all seperatly.
So I bought new gears for the internals, and have a new diff case ordered, as I tried to take the gears out of the old case, and it seems that the case has melted causing the gears to move around so that only 3 of the little spider gears are engaging.
And in the process it melted one of the mounts where the bearing seats
So I can't even lock it till the new casing (and mounts) arrive...
On a side note, I'm converting one of my other nitro 1/8 buggys from 48T centre diff to a 2 speed 45T/50T locked transmission.
What sort of characteristics does a locked centre diff give over a conventional geared diff?
Is there a chance I will ruin the buggys handling greatly for a bit more acceleration/top speed?

My ST-RR EVO

iTrader: (5)

This partly depends on the power of your engine and the traction level you have.

Top speed will not be affected.
Generally speaking- a thicker and / or locked diff will increase acceleration if the traction levels are high enough, like running on asphalt with the right tires. If traction is not high enough, you'll just spin up the tires.
The car will be harder to drive. Imagine a 2wd mod buggy with bald tires on loose dirt. The rear will want to step out on you in a frustrating way. If your engine doesn't have much power you may not notice. My opinion is that building the diff with fluid in it is the best way to have an enjoyable buggy to drive.

curacing2

Your buggy will be very loose in the rear and it will put extra strain on your rear diff and gears so check they are shimmed good and tight.

are you a Kiwi Jay and where do you race/thrash?

Craig

KiwiJay

Cheers for the advice mate,
And yes, I am a kiwi.
Though I live in Australia in Queensland.
There's a few tracks around me here in Brisbane