Trail gear 4.7 kit

Thudson · Sep 13, 2016

Has anyone ever had the trail gear 4.7 splines strip? I'm running 2.28/4.7 doubler. It seems like the metal was not hardened. ???

uglyoffroad · Sep 13, 2016

That exact same thing happened to me a few years back. I believe the needle bearing that slides into went bad too. I assume the bearing went bad first and allowed the gears to seperate too much. May have been the other way around though. I was told that the trail gear bearing was a cheapo and the Marlin kit had a better bearing. Trail gear did warranty it for me and they said they were going to put a better bearing in this time. I didn't have problems after that but also sold the buggy about a year later.

Thudson · Sep 13, 2016

Wow... seems like a common problem. Its only been on 4 good rides. But I am running 39 reds.

RebelRider · Sep 13, 2016

What gear were the cases in? I busted mine, but didn't strip the gears. I was pushing it too hard with the front case in high and the rear in low. TG was a little hesitant, but Daves Performance helped me get them warrantied. I parted the cases and never went back.

TBItoy · Sep 14, 2016

Re:

Those failures are not uncommon, with any gears.

I've had a set of Marlins and TG blow on the low range side. The stock housing is what fails first in my opinion.

And if you run duals without upgrading the rear case to 23 spline, you WILL break the 2nd case 21 spline input.

blacksheep10 · Sep 14, 2016

Second guy said he was in front case high, back case low. This should be the same as a single case with low gears, no multiplication and no doing the low front/high rear thing asking for intercase breakage. Seems like if its blowing up on the low side gears the reduction is great enough to let something deflect/spread and come out of good mesh and blow up, or they are shoddy material/design/hardness

TBItoy · Sep 14, 2016

blacksheep10 said:
Second guy said he was in front case high, back case low. This should be the same as a single case with low gears, no multiplication and no doing the low front/high rear thing asking for intercase breakage. Seems like if its blowing up on the low side gears the reduction is great enough to let something deflect/spread and come out of good mesh and blow up, or they are shoddy material/design/hardness

Yep, it's the dana 300 case syndrome. I've replaced several case pieces that were cracked and leaking from 4.7 gears pushing them apart.

Thudson said:
Wow... seems like a common problem. Its only been on 4 good rides. But I am running 39 reds.

What axle gear ratio are you running?

IMO anything less than 4.88 and you're gonna blow cases on the reg if you wheel hard on those tires.

The AA reduction housing will keep the 4.7s together better too.

http://www.advanceadapters.com/products/51-5911--heavy-duty-toyota-truck-gear-driven-transfer-case-gear-reduction-housing/

blacksheep10 · Sep 14, 2016

TBItoy said:
What axle gear ratio are you running?

IMO anything less than 4.88 and you're gonna blow cases on the reg if you wheel hard on those tires.

For everyone else's clarification, I'm Assuming you mean numerically less, like if you run 4.10 you're going to have problems with upstream stuff, drivelines, tcases, etc. If you run 5.13 and up you're easier on upstream parts.

TBItoy · Sep 14, 2016

Re: Re: Trail gear 4.7 kit

blacksheep10 said:
For everyone else's clarification, I'm Assuming you mean numerically less, like if you run 4.10 you're going to have problems with upstream stuff, drivelines, tcases, etc. If you run 5.13 and up you're easier on upstream parts.

Correct. Less as in less reduction.

Thudson · Sep 14, 2016

I'm 2.28 front 4.7 23 spline rear. I have a rcv cromo rear output shaft as well. I was in low low when it happened. The only time I take it out is when trail riding and then I just run low front and high rear.

blacksheep10 · Sep 14, 2016

Thudson said:
I'm 2.28 front 4.7 23 spline rear. I have a rcv cromo rear output shaft as well. I was in low low when it happened. The only time I take it out is when trail riding and then I just run low front and high rear.

Depends on how good the intermediate shaft is, but on 203/205, front low rear high was a bad idea as the reduction upstream would break the larger load (less reduction) downstream at the weak link, which was a resplined shaft between cases. Moot for gear failures

Thudson · Sep 14, 2016

It ran fine with it in low front and high rear. I wheeled the rest of the day just did not have low in the rear. On my buggy i don't run my 203/205 like i do in the yota I would run high front, low rear.

alscott · Sep 14, 2016

I broke the 4.7 TG input in the rear case on mine not long ago. It had a hard life, I put toy gears back in it and run both cases in low now unless im cruising.

zukimaster · Sep 14, 2016

Here is a pic of the TG 4.7 gear after my front driveshaft let go.

Sent from my XT1080 using Tapatalk

Thudson · Sep 14, 2016

Nice!

Thudson · Jan 4, 2017

Aop riot hill 4th gear. Broke another tg 4.7. I'm kinda getting tired of pulling out these tcases every other ride lol

zukimaster · Jan 4, 2017

If I were you and continued to keep using the Toyota cases, I would go with Marlin Crawler stuff, I believe it would hold up better than the made in China trail gear stuff.