OG Mammoth and ST

[trxnitrosport]

Ok, I have both a OG Mammoth and an ST. My OG mammoth just stripped the gears in the rear diffs this past weekend. What causes steel teeth to be torn? Also, on my ST, when I hit a certain RPM range, I hear a clicking noise. Usually when the truck is about to shift or just as it's shifting into 2nd gear. Can anyone help? Thanks.

Oh forgot to mention that on the OG mammoth, the fuel is leaking out from under the glow plug. I've tightened that up and also check the head to see if there may be a leak. Any suggestions?

 

[vbgagnon]

With the force that these little engines put out stipping steel gears isn't that hard. With your diffs you could have had a loose bulk head, or it could just be an old gear.

With your st it could be the bearings are going bad in your 2 speed. Many people change out the 2 speed with a diff in those trucks so it becomes more like a true truggy.

The fuel leaking out of the glowplug hole. Is it leaking inside the heat sink or under it. If it leaking inside then you either have a bad plug or a bad copper washer that goes under the glow plug.

If it is leaking under the head then you may need to replace the head shimms.

 

[digger]

Shim the diffs when you go back together. About 3/4 down on this page. and part of the next one. http://www.racernine.com/outlaw5.html

Have you tried a new plug on the engine? Maybe the copper washer is bad?


posting at the same time VB. Old guy is kinda slow.

 

[olds97_lss]

The OG mammoth has poorly shimmed diffs from the factory and were very prone to stripping. The ST has shims in the diffs, but they still need maintenance from time to time.

I switched to a center diff about 3/4 of a gallon ago and I run an axial 28 without any issues. The two speed is nice, but it's hell on a truck without a slipper. Every time it shifts into second, it's slamming the driveline. Plus, it's geared low, so pegging the throttle off the line with 1st gear is slamming the diffs as well. The 2 speed in the mammoth is a poorly executed stretch at trying to get people to buy a truck that handles better than a typical MT, but has the same top speeds and torque off the line as a MT.

If you go with a center diff, your maintenance on diffs will go down, but there's a trade off of off the line acceleration and top speed. Since I'm just a basher, I don't mind the trade off. I'd rather have a rig that lasts weekend after weekend with minimal repairs.

 

[digger]

I've still got the 2-speed in mine. Haven't been able to run it much though.

You make a good point Olds. I never had thought of the truck not having a slipper. Guess that is hard on the diffs.

Have you guys seen these? http://www.hobbypeople.net/gallery/149895.asp
Made like the Savage diffs.

 

[nitrohead]

Digger, those diffs will take care of the problem!!

 

[digger]

Digger, those diffs will take care of the problem!!

Need these too if you are going that way. http://www.hobbypeople.net/gallery/149893.asp

Wonder if it has 4 spider gears or 2?
Pic shows 2 gears, but shows the pins for 4?

 

[olds97_lss]

The output shafts/cups from the two speed work.

What I did when I got my center is I ordered just the center spur from hobbypeople ($25) and ordered a complete ST front/rear diff from ebay ($25). I took the new diff (ring/cups/pinion/bearings/diff cup/planetary) and put it in the rear and the cup+planetary+outdrives from the old rear diff and mounted it in the center. The inner gears/shafts/cup/seals were fine in the old rear diff. It was the ring/pinion that had wear.

I got the equivalent worth of a complete center and brand new rear diff (center diff + rear diff + diff case + pinion+ gearbox+ outdrives + bearings ($50+$45+$10+$13+$10+$8 +$9=$135 @hobbypeople) for a total of $50 by only buying the center at hobby people prices and a complete front/rear diff off of ebay.

The complete center diff from hobby people is $50 without outdrive cups. The complete rear/front diff is $45. For that, I could have scrounged and found at least 3 complete diffs with cases, bearings, gearbox's and had spare change on ebay.

Just because it's a hobby doesn't mean you can't be frugal when shopping.

 

[digger]

Says output shafts are required for the spider diff? Am I posting the wrong link or missing something?

Sorry Bro. Just trying to get it straight.
If I buy the spider diffs, I don't need the output shafts?


I'm not frugal, I'm tight as hell.....

 

[nitrohead]

The originals are not the right size they need to be replaced with longer units.

 

[olds97_lss]

Says output shafts are required for the spider diff? Am I posting the wrong link or missing something?

Sorry Bro. Just trying to get it straight.
If I buy the spider diffs, I don't need the output shafts?


I'm not frugal, I'm tight as hell.....

Sorry, I didn't realise that. I didn't upgrade to spider diffs. I still have the original diff style.

 

[nitrohead]

Yeah they are talking about a different style diff and the fact that you also need new outdrive cups

 

[trxnitrosport]

Will the diff assembly for the savage fit directly into the diff case for the mammoth and will this help solve my problems? The outdrive cups on the rear keep coming loose no matter what I do. Check these out and let me know if they'll fit.

http://www.hobbypeople.net/gallery/228569.asp