Topic: Cruiser Dave ( Problem with SM420 to Toybox ) need help

[smtyblt]

this is posted for a freind of mine Tim

bought your tobox threw Ironpig Offroad do mate to his SM420 and can not get the input gear onto the 10 spline output gear

NEED HELP

[LCOwner]

Need more information.  What appears to be keeping it from going on?  Inner splines of the tcase input?

[smtyblt [OP]]

the problem seems to be in the 10 spline gear in the toybox,  A 10 spline 3 speed landcruiser gear slides right on the sm420

[jester]

Hey everybody.  I'm Tim.  Been trying to get in touch with Dave for a few days now about some questions with a MC20 - MC23 Toybox install.  Got a call from him today but wasn't at home to take it and couldn't get through the phones at MC again.  Made the mistake of mentioning this to my overzealous friend Smtyblt who started this thread to try to help me out.  Good old Smtyblt...

So here are my questions and issues for Dave or whoever might know:

I can't get the Toybox to slide onto the Output Shaft of the SM420 output to save my life.  The old LC 3spd TC input gear was tight but will slide all the way on by hand if you get it aligned right. I first checked for and removed any burrs by hand with emory cloth. No go.  I polished the ID of the Toybox (using a socket wrapped with 400 grit) and the OD of the SM420 output.   Now the LC 3spd gear goes right on, but still no go for the Toybox. I then marked the entire SM420 output shaft with a soapstone and tried to slide it on again to see if I could determine how far it goes on and where it hangs up. Well the splines never engage. It seems that the ID and OD are fine, but the "male" splines on the SM420 are too wide to engage the female splines of the Toybox.  Whats up with this?  Do I need to have the SM420 output shaft machined or is this a problem with the Toybox input?

Does the split ring go right against the SM420 mainshaft bearing, or should there be a thrust washer/spacer in there? One side of the split ring has a small groove machined in it - does this face the transmission or the Toybox?

I can run the SM420 Countershaft Rear Bearing Retainer and Lock Plate with the MC20 adapter right? (It hit the old adapter I use to have and was told to leave it off, which I was never comfortable with. My truck has still not moved under it's own power since I got it so no damage could have been done.)

I hope I was supposed to remove the three allen head bolts that were retaining the bearing on the back of the Toybox and knock in the machined aluminum spacer. Seemed to make sense to me and it was the only place I could find for it to go. Not sure I can get it back out without damaging it. It was a tight fit over the retaining clip. The allen head bolts seemed to be red locktited - for shipping I assume?

I pulled the Splitcase a month or so ago off a parts 60 and forgot a little bit about how it came apart. It was either missing or I have lost the PTO gear. I have some pics somewhere of the teardown, but can't find them on my computer. Do I need the PTO gear? In addition to the input gear, I still have a 2 3/16" spacer, a 9/16" spacer, and the three single and one double thrust washers that came with the Toybox that I assume all go on the output shaft of the Toybox in some specific order before the new nut.  I don't know what this order is.

Dave - sorry I missed your call today.  I'll try to reach you tomorrow or give me a call after 7 PM EST.

Thanks,

Tim Minner
Bowling Green VA
Bay to Blue Ridge Cruisers

[cruzila]

Hey everybody.  I'm Tim.  Been trying to get in touch with Dave for a few days now about some questions with a MC20 - MC23 Toybox install.  Got a call from him today but wasn't at home to take it and couldn't get through the phones at MC again.  Made the mistake of mentioning this to my overzealous friend Smtyblt who started this thread to try to help me out.  Good old Smtyblt...

So here are my questions and issues for Dave or whoever might know:

I can't get the Toybox to slide onto the Output Shaft of the SM420 output to save my life.  The old LC 3spd TC input gear was tight but will slide all the way on by hand if you get it aligned right. I first checked for and removed any burrs by hand with emory cloth. No go.  I polished the ID of the Toybox (using a socket wrapped with 400 grit) and the OD of the SM420 output.   Now the LC 3spd gear goes right on, but still no go for the Toybox. I then marked the entire SM420 output shaft with a soapstone and tried to slide it on again to see if I could determine how far it goes on and where it hangs up. Well the splines never engage. It seems that the ID and OD are fine, but the "male" splines on the SM420 are too wide to engage the female splines of the Toybox.  Whats up with this?  Do I need to have the SM420 output shaft machined or is this a problem with the Toybox input?

Does the split ring go right against the SM420 mainshaft bearing, or should there be a thrust washer/spacer in there? One side of the split ring has a small groove machined in it - does this face the transmission or the Toybox?

I can run the SM420 Countershaft Rear Bearing Retainer and Lock Plate with the MC20 adapter right? (It hit the old adapter I use to have and was told to leave it off, which I was never comfortable with. My truck has still not moved under it's own power since I got it so no damage could have been done.)

I hope I was supposed to remove the three allen head bolts that were retaining the bearing on the back of the Toybox and knock in the machined aluminum spacer. Seemed to make sense to me and it was the only place I could find for it to go. Not sure I can get it back out without damaging it. It was a tight fit over the retaining clip. The allen head bolts seemed to be red locktited - for shipping I assume?

I pulled the Splitcase a month or so ago off a parts 60 and forgot a little bit about how it came apart. It was either missing or I have lost the PTO gear. I have some pics somewhere of the teardown, but can't find them on my computer. Do I need the PTO gear? In addition to the input gear, I still have a 2 3/16" spacer, a 9/16" spacer, and the three single and one double thrust washers that came with the Toybox that I assume all go on the output shaft of the Toybox in some specific order before the new nut.  I don't know what this order is.

Dave - sorry I missed your call today.  I'll try to reach you tomorrow or give me a call after 7 PM EST.

Thanks,

Tim Minner
Bowling Green VA
Bay to Blue Ridge Cruisers

[LCOwner]

That's interesting that the LC case gear will slide right on but the MC gear won't.  Was this 420 in front of the LC tcase before?  Is it possible the main shaft has been changed or modified? 

[jester]

I pulled this SM420 from a big 1960 GMC truck at the local junkyard.  Still had all the original 2wd tailhousing and e-brake setup so no I doubt the mainshaft has been changed or modified.  I'm not sure if the age of the 420 has anything to do with it. 

I had a 3spd TC bolted to it for a while, but never really finished the install and decided to go with the Toybox/Splitcase instead when the $ became available.  We are about 30 months in to a 12 month build 

Yes the LC 3spd input gear goes right on now after all my polishing/deburring.  I tried for two days to get the Toybox to slide on and kept convincing myself that I still had a burr or it wasn't aligned just right.  It just starts to go, but I think that is the taper on the shafts as they align.  Then it gets stuck and I have to carefully pry and tap it off, even though I've coated it with 80/90 to lube it. 

[jester]

After talking with Dave for 30 minutes or so today, the crawlbox is going back to him for evaluation. If it slides right on to their shop SM420, I'm going to pull the mainshaft out of my SM420 and send it to them to see if it was the problem.

I'll post an update when I figure this out. Thanks to all for your responses concerning this and the other questions I had.