LOSI LST XXL Conversion ideas - Page 22 - RC-Monster Forums

JThiessen · 07.18.2010, 04:14 PM

Yeah, we'll just settle on cheap bastard!!!

mistercrash · 07.19.2010, 10:25 PM

I couldn't wait for the 5 ID X 2 mm cross O rings to come in so I found O rings at the hardware store that had imperial measurements that were close enough and reassembled the front shocks with the 5 mm shafts I made and the valves for the shock pistons. I also got some M4 screws to replace the hinge pins. I went with the 60 mm long ones and the shoulder was just right. I just had to cut the excess threads since the shoulders were so smooth I didn't feel the need to polish them. only the front suspension is done for now. I bashed it on 6S and it all worked very well. The 5 mm shafts held up but more testing needs to be done. The wrong sized O rings didn't leak but I suspect they might because they didn't fit as tight as they should around the shafts. The shock straps worked great, more testing needed on those two. The hinge screws worked awesome and let the suspension move very freely. The piston valves really seem to give more damping on hard landings. I noticed a lot less bottoming out. The over stuffed Proline Mashers are excellent for bashing, they give good grip on many surfaces and the over stuffing firms them up quite nicely giving a lot of support for this heavy truck. I'm very pleased.

mistercrash · 07.21.2010, 10:36 AM

A little while ago, the pinion and internal gears stripped in my rear diff. I repaired it thinking it was just what happens when you bash too hard. A couple days later, I blow the internal gears of my front diff and a pinion in the rear diff. I thought I was just unlucky. Yesterday, the internal gears of the front and rear diffs blew. This is a problem. I can explain pinions stripping if I didn't shim correctly but internal gears, there's not much I can do in there. I use the Losi HD diff cases so I'm baffled. What can cause the innerds of my diffs to strip so often?

Bondonutz · 11:48 AM

I do my best NOT to drive on the street or concrete. The high traction surfaces are death to diffs under 6s power.
Sorry to state the obvious Ray, loosen the slipper a touch !

nuz69 · 07.21.2010, 11:40 AM

Punch control !! (Especially if you drive on High grip surface)

mistercrash · 03:51 PM

Your comments and suggestions are welcomed, no need to be sorry. My slipper is set correctly, I'm pretty anal in checking it often. I can hear it work constantly when I get on the throttle. That short ''whizzzz'' it makes when it slips. I will check my punch control settings and I will probably make sure my slipper is set correctly again (anal I told you).
I will definitely not avoid running on any surface I wish to though. But maybe I'll try to remember to take it easy on high bite stuff. I feel that a construction site where I bash most often is the worst for the drive train. Sand, rocks, dirt, wood, piece of concrete, bumps, ruts, hills etc. All these give different traction to each wheels. Slip, grip, slip, grip a lot, grip a little, slip a lot, slip a little, grip a lot, at a different rate for each wheel all the time, I think that is way more difficult on the diffs then the linear traction you get from asphalt or concrete. I may be wrong but I noticed that I never seem to break drive train parts on concrete, asphalt or grass, always when I go have fun in those construction sites. Anyway.
After I opened the diffs and cleaned every part, it was obvious that it was the spider gears again that stripped a few teeth which caused a little damage to the output gears. Here's what I'm going to try, I had a couple sets of rebuild kits for the Thunder Tiger S3 buggy and I'm going to try those spider gears. After comparing them with the Losi ones, they seem better made with more meat on the teeth.

The Thunder Tiger spider gears are on the left

Here's a different view that makes the differences easier to see. Both gears have the same number of teeth and the same pitch. But the Thunder tiger spider gear has a slightly bigger diameter and is thicker. This results in the teeth being longer and having more surface to mesh with the output gears. I hope that it makes them stronger.

The Thunder Tiger diffs also use thin shims behind the spider gears and the output gears. So I installed the shims and the spider gears from Thunder Tiger and all the rest is Losi diff parts. It all seems to work together and the diffs are very smooth. Now to go out and try them.

mistercrash · 07.22.2010, 06:48 PM

After 4 cycles on 6S the Thunder Tiger spider gears are still holding.

mistercrash · 07.23.2010, 11:10 AM

We went out to play with the trucks this morning and after bringing the LST back after the first set of lipos, I noticed that the rear diff felt notchy when turning the wheels by hand. And all of a sudden, it locked.

I took the diff out again opened it, cleaned every part and the problem was a single tooth broken from one of the Losi output gears. The severed tooth was floating around in the oil and locked the diff. The Thunder Tiger spider gears are fine so I replaced the Losi output gear and put everything back together I'm out of diff parts and diff lube.

mistercrash · 07.23.2010, 10:07 PM

After spending some time this morning rebuilding the rear diff, I blew it again this afternoon and I was running on 4S. Same problem as last time, the Losi output gears broke a tooth or two. It seems that the Thunder Tiger spider gears are too hard for the Losi output gears. I'm thinking Hot Bodies Lightning buggy diffs

http://cgi.ebay.com/HOT-BODIES-C8178...item3effd0febe

With a 13 tooth pinion also from Hot bodies

http://cgi.ebay.com/HOT-BODIES-C8030...item5ad96933ff

I heard they are really tough, I just don't know if they fit the Losi LST XXL diff cases. I searched these forums for an answer and I got a conversation between ''its me'' and ''angry alien'' about it but never found a definitive answer. So I'm still wondering if it would work. Anyone know for sure?

On another note, we all know that it's not good for our sensitive equipment but a perfect mud puddle is totally irresistible. Pics of my LST and my son's Brushless E-Revo from this afternoon.

lincpimp · 07.24.2010, 10:34 PM

Hmm, I have never had an issue with breaking the diff output gears, I run nova rc al cups, with the tin coated gears. Stock lst diff internals. Are you using the al cases for the diffs? I run the dull looking aftershock cases. I also run 30k diff fluid in the diffs...

mistercrash · 11:16 PM

Yes I run the aluminum diff cases, 10K in the rear and 30K in front. Here's the problems I had with XXL diffs. Snapped off drive cups twice, broke teeth on the little spider gears in the front diff once and two times in the rear if I remember correctly. Changed to Thunder Tiger S3 Buggy spider gears that I had lying around in the rear diff. Now it's not the TT spider gears that break, it's the output gears which are the original Losi ones. Looks like the TT spiders are too hard for the Losi output gears. My slipper slips like crazy, I can't even wheely. The LST XXL diffs were very tough in my E-Revo, but the LST weighs about 3 pounds more. The diffs don't seem to like that. I got a set of hardened internal diff gears from Hot Bodies coming in. I bought them even though I don't even know if they will fit. I think they will, at least I hope they do.

Manne · 06:43 AM

Hm and I who was thinking of getting building a lst due to the revo´s diff problems...seems to me like we need the manufactors to re design the diffs in the most Mt´s, beef them up a bit.

Nice mudding

lincpimp · 07.26.2010, 10:15 AM

Quote:

Originally Posted by mistercrash

Yes I run the aluminum diff cases, 10K in the rear and 30K in front. Here's the problems I had with XXL diffs. Snapped off drive cups twice, broke teeth on the little spider gears in the front diff once and two times in the rear if I remember correctly. Changed to Thunder Tiger S3 Buggy spider gears that I had lying around in the rear diff. Now it's not the TT spider gears that break, it's the output gears which are the original Losi ones. Looks like the TT spiders are too hard for the Losi output gears. My slipper slips like crazy, I can't even wheely. The LST XXL diffs were very tough in my E-Revo, but the LST weighs about 3 pounds more. The diffs don't seem to like that. I got a set of hardened internal diff gears from Hot Bodies coming in. I bought them even though I don't even know if they will fit. I think they will, at least I hope they do.

Pretty sure the hb hardened gears do not fit. I tried when I built my lst diffs and to the best of my memory they did not fit. The hb diff is wider than the losi, so the internals are thicker.

mistercrash · 07.26.2010, 11:46 AM

Well then I don't know what to do. The rear diff gave out again this morning. Again I was running 4S. I'm completely out of parts for now so I can't repair it. I have been racing and bashing for 25 years but I don't remember having this much problems with diffs. It's a bit sad, after all this work to convert this LST, I don't feel like repairing it right now. There's a problem on that truck but I don't know what it is. Until I can find what the problem is, I don't want to just keep on breaking rear diffs.

JThiessen · 07.26.2010, 01:25 PM

Have you double checked to make sure you are getting power to all 4 wheels? Wonder if maybe your putting all the power to the rears?

Troubling issue...hope you can figure out what it is.