JRX2 'RETROFIT' XX gearbox help needed.

[Bormac]

I have some parts to make up a XX retrofit gearbox and wanted to see if anyone can help me in my quest to bolt this thing into my original JRX-2.

What i have is- A-3054 XX (retrofit trans case 2.19:1 ratio)
A-3074 XX (trans diff gear 2.19:1 ratio)
A-3010 (diff rings)
A-3079 (idler gear XX)
A-3078 (diff screw & seal set)
A-3056XX (retrofit trans slipper shaft,etc)
A-3072 (trans diff tube XX)
2x A-3082 (retrofit truck dog bone XX)
2x Used steel diff outdrives for dogbones.

What I would like to end up with is a retrofit trans that runs the original slider driveshafts. I would like to atleast keep those original to this car so I wont be needing the dogbone driveshaft parts. If you have a complete set up you'd consider trading or could point me in the right direction of the parts I need to complete this build i would be very greatful.
Thankyou- Jason.

[aconsola]

I don't know that there are any outdrives for sliders on that trans. I thought they all came with dogbones for the conversion, but could be wrong.

The Buggy dogbones are still readily available, LOSA3081.

do you have the manual for the retrofit gearbox? if not it can be found here:
http://www.vintagelosi.com/Manuals_files/RetrofitXX.pdf

[aconsola]

well I guess I was using a parts list that was too old. it looks like these are the outdrives you need:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=110377532078

I believe that the universal pivots for them are different than the regular ones:
http://www.losi.com/Products/Features.aspx?ProdId=LOSA3096

[karnivool]

yes they were dogbone in the retro fit kit.

[JPAE07]

Are those all the parts needed? Internals...etc?

Just wondering b/c I would like to put one together if I can find the parts.

[m2fit4u2]

Did you build your trans yet?

I am having trouble getting my XX (retrofit) trans to work silky smooth like my XXX and XXXT transmissions. It just seems like there is to much drag.

[bearrickster]

if you need some of those outdrives for the sliders I have a bunch let me know I can hook you up

[JPAE07]

I have almost all of the parts now to complete the retrofit trans with the exception of the diff balls, bearings, spur, and top shaft.

Does anyone know what the difference is between the a-3056 topshaft per retrofit instruction manual and the a-3060 topshaft?

I purchased an a-3060 which says xx transmission topshaft on the header card. why wouldn't it work?

Thanks in advance.

[mrlexan]

Try out and see what happens. Make sure to let us know what you find out. I'd like to know myself. Good luck.

[karnivool]

Did you build your trans yet?

I am having trouble getting my XX (retrofit) trans to work silky smooth like my XXX and XXXT transmissions. It just seems like there is to much drag.

might be a stupid call, but did you degrease your bearings?

[Charlie don't surf]

Did you build your trans yet?

I am having trouble getting my XX (retrofit) trans to work silky smooth like my XXX and XXXT transmissions. It just seems like there is to much drag.

might be a stupid call, but did you degrease your bearings?

And/or break in the gears with an abrasive compound in it's direction of rotation?
that tranny was my first ( d^%m I hated that tranny, Sorry Menoti!) losi tranny in a
LXT and it was never, ever smooth--2 hrs packed with polishing compound at 15000 rpm
and after it was about 10% smoother.

[m2fit4u2]

Thanks for all the advise.

I have the diagram for the XX retrofit chassis, but I still had to add a spacer and bearng to the outside of the slipper shaft in between the slipper clutch plate and trans housing. Without these my slipper clutch plate was rubbing against the metel motor plate. There is a much deeper slipper shaft well (on the outside) in this trans than the newer XXX trans.

The trans is running smoother every day. When I installed new gears, there seemed to be some drag. After just slightly snugging the trans bolts, using a tiny bit of gun oil instead of the losi trans grease, it now is getting smoother and spinning for awhile when the motor is not installed. I still might try that polishing compound, that sounds like a good idea. Other than that, the trans seems to be very strong and holding up well with my brushless system.

[JK Racing]

I have built many-a-retrofit tranny, and I have run across a few that are tight, no matter what I did. One thing I did notice is you cannot get the tranny free and smooth with the aluminum top shaft. I think the coating messes up the gear mesh. I ran the tranny in for a few battery packs and it was still tight. My buddy ended up installing it in his LXT, and after about 10 packs on it (with a 17.5) it is decent, not good, but decent only. We swapped out top shafts and it was as smooth and free as any other tranny I have ever built. He decided he wants the aluminum top shaft still, so he swapped it back in.

Could have a warped case? Odd bearing?

[Brandon G]

My $.02....

Look for a slipper conversion for the original tranny and run it instead.

I ran the retrofit in my Pro at the last vonats and I wasn't impressed. Seemed like the guys running the original box had more punch and top speed than mine. I tried a gamut of different gear ratios too.. I didn't like the diff in the retrofit tranny either. Very touchy. Seemed like it needed to be tightened down A LOT to keep from backing off and slipping. (all new parts were used BTW)

[aconsola]

Thanks for all the advise.

I have the diagram for the XX retrofit chassis, but I still had to add a spacer and bearng to the outside of the slipper shaft in between the slipper clutch plate and trans housing. Without these my slipper clutch plate was rubbing against the metel motor plate. There is a much deeper slipper shaft well (on the outside) in this trans than the newer XXX trans.

The part was changed somewhere along the way. The original inner plates had a deep shoulder to them. More modern versions are more shallow and include a spacer for use on the xx/retro. I think I have an instruction sheet somewhere explaining this.