930 Drive Line for Dummies

[justooln2]

930 Drive line for dummies.!

This is my first build. I have a rolling chassis that I got off ebay. Its almost exactly what I had planned to build. A little chop here and re-weld there and I’m good to go. Ive got a few 93 Yamaha FZR 600cc and the mini rail im working on has a 98% complete 2002 Honda F4i. I need the fuel pump, radiator and a few other minor things.
The front end is Done. The rear has Trailing arms, Vw hubs and 930 CV axles. No actual center bearing carrier or drive sprocket.

I understand how the 930 goes together to make an IDS setup. Ive got the outer hubs, the CVs the CVaxle shafts and the inner CVs.
So now im wondering, Where exactly to weld the imaginary center bearing carrier? If its welded in the wrong place, I will bind my CVs and would need plunge axles. So with some math I can figure that part out, I think. The correct arch ect ect. , Gooose flab bla..

What is the 930 Stub shaft used for? Is that the outer part where the wheel hub and wheel bearing attach?

Where are the Center splined shaft coming from? Are they custom machined? Is there an off the shelf shaft?
Next is the two center CV flanges that attach to the splined shaft. As I understand it, if my splined shaft is not the correct length, with fairly close tolerances it will cause compression or stretch in my rear trailing arm geometry. So if I ask Proto or Yoshi to build me one, will they need to know flange to flange OAL, or do they just say hey, its an 8” shaft deal with it?

Has anyone used a 930 Stub for the center shaft? Hell its already got one 930 flange on it. Add to bearings, bearing cases and another 930 flange your good to go.? Right?

Ive emailed Yoshi already, and DesertKarts too, haven’t heard anything back as of yet.
I’m probably going to buy from ProtoDie because he seems to have the best bang for my buck.


Anyhow. Thanks for your help and im looking to being an actual mini rail owner.. PS anyone in the Central Illinois area, let me know. Thanks Don aka justooln2

[nutz4sand]

Welcome to the site.

Others will pipe in soon but in your pic it LOOKS like the rear axles go forward from the spool area. The pics dark (hard to see some of it) and at an angle that might be throwing it off but it sure looks like that. It also looks like its jsut laying there till yu get it figured out so maybe you already know this below? If not its important.

The first and most important thing is if the motors mounted you need to line the sporcket up with however you do build your spool.

Next is clearance. The lower it can be the better for CV angle BUT you need ground clearance. A big sprocket gets the gearing you need but hurts a low center section. A jackshaft adds parts but is somtimes a needed evil.

Next is back to what I am refferring to the arms appearing to go forward from the spool area.

Trailing arms are the WORST when it comes to axle plunge (VS A-arms and Five link types). If you are going for a lot of travel and the longer arms suggest you would like this then as the arms raise the axles are CLOSEST to the spool when they are level with it.

Most trailing arm systems try to get it so that trailing arms are dead center under the spool at full droop (IF you droop that far) but that the shafts are always even with or prefferrably behind the spool/or/diff. As the arm rises it moves the wheel/spinlde/hub AWAY from the spool (due to it following the arc it does) and as the axle TENDS to get closer as it approaches level due to the UPWARD motion the BACKWARDS motion helps to compensate for axle length by moving the hub and spindle backwards.

If the spool really is behind the spindle like your looks like it is then asthe axle raises it will get closer in arc AND height and likely cause a bottoming issue in the CV's.

Unless you have accounted for this already??

[K-fab]

Welcome to the site!

Originally Posted by justooln2

I understand how the 930 goes together to make an IDS setup. Ive got the outer hubs, the CVs the CVaxle shafts and the inner CVs.
So now im wondering, Where exactly to weld the imaginary center bearing carrier? If its welded in the wrong place, I will bind my CVs and would need plunge axles. So with some math I can figure that part out, I think. The correct arch ect ect. , Gooose flab bla..

I think Nutz pretty much covered this. The farther forward in the chassis (closer to the pivot point line between the two arms), the less plunge you'll have, but you start over articulating the CV joints. 930s don't like to work well after 25-26 degrees.

Originally Posted by justooln2

What is the 930 Stub shaft used for? Is that the outer part where the wheel hub and wheel bearing attach?

Starting from the outside inward, as if you were assembling:
Nut, hub, (sometimes spacer), bearing carrier, stub axle, CV, axle, CV, CV Flange, output (of what ever - tranny, chain setup).

The shaft stub goes through the bearing carrier, sometimes there's a spacer, then the hub slips over the splined end of the shaft and the nut holds the whole thing together.

Originally Posted by justooln2

Where are the Center splined shaft coming from? Are they custom machined? Is there an off the shelf shaft?
Next is the two center CV flanges that attach to the splined shaft. As I understand it, if my splined shaft is not the correct length, with fairly close tolerances it will cause compression or stretch in my rear trailing arm geometry. So if I ask Proto or Yoshi to build me one, will they need to know flange to flange OAL, or do they just say hey, its an 8” shaft deal with it?

The closer you can make the flanges together, the better - will allow for longer axles, which make for less angle on the CV joints. I believe that more than a few of the guys here on the site have purchased a piece of splined shaft, built up their rear ends and then cut the shaft to fit. Hardest part about that is grooving the shaft ends if you don't have access to a lathe.

Someone will chime in where to get the shaft. Ask bugpac where his came from. I can't recall if it was McMaster-Carr or Tractor Supply... (and where did I come up with Tractor Supply if he didn't use them? - who knows... )

[CarolinaRigman]

I like your setup! But I do think your a little cramped for space.
I went through the same delima.
Does anyone offer a CV flange that adapts to a 1" keyed shaft?

[Greg@desertkarts]

justooln2, I'm not building them anymore.
Greg@Desertkarts.

[justooln2]

Thanks everyone. It seems like I am on the right path. The Engine is not mounted, and there is no Center carrier. So the axles have no path as of now. So they are not going forward of the spool. With my trailing arms, as they compress, if I have binding issues, Ill just chop it up and get some DOM and Heims and do a tailing arm/ link like that of the Drakart. I am going to have to call BS on this one; supposedly my rear trailing arms have 18” use full travel. That may be true while there is no center carrier to mess with the arch and spindle geometry. Like I said, BS. Until further notice.
When contacting Tractor Supply, do I just ask them for a 1 3/8” 33 spline shaft X” long?
Ive a tractor supply 5 minutes from my house. And I may be able to get a McMaster-Carr order in through work.
I do not have access to a Lathe, I am keeping my eye out for a Lathe and Mill but no luck yet, either find it and no money, or got the money but cant find one. And I can never keep a hold of the money very long. Im good a making it, and even better at spending it.

Here is a pic that may show the rear a little better.


To (Greg@Desertkarts) Sorry to hear your not building center carriers any longer.
I like your site, and your plans are pretty good. Is everything else on your site still available?

Thanks guys, Can’t wait to actually meat up with some mini rail owners and get dirty.
Cliffs Insane Offroad park is 1.25 hours from my house. And I’ve only broken my Jeep there once. WTF yo???

Don

[nutz4sand]

I have never asked at Tractor supply about different splined shaft available but I should to see what they might have. As for now I think its only common Tractor fits which are either square tube type or like six or seven BIG thick splines (Typical tractor PTO)

18 inches is easy to get an arm to swing. BUT the means of transferring power while it does may be tough or at the minimum $$$. Glad to see you know that already.

Pop up some clearer pics when you get some light if yah can.

[nutz4sand]

Yah posted that pic while I was typing.

If you place the outside cvs as close as you can figure to the migdle of thier plunge with the axles as level as they can be how close together is the middle??

How strong are those trailing arms? Can you twist them at all if you really try?

[ttginc]

I got my center splined shaft from Kaman Direct. In fact, I have an extra Hub Cuty Involuted Spline Shaft - 1 3/8" 21 spline shaft 12" long with a 1.75 OD coupler that you could weld to some CV cups. I cut mine down to the length I needed. It is very similar to Protodie's set up. I run the 1.75" OD bushing inside my bearings to allow for a shorter center length. The CV cups are plates cut on a waterjet, TIG welded together, and faced on a lathe. Not the nicest cups out there, but they work well. You could simply find a 930 cup and weld the splined hub adapter in it. The bearings are mounted in a pivoting plate box that acts as the chain tensioner as well. I hope this helps.
Send me a PM if you are interested in the shaft and bushing.

Jeremy

[ttginc]

Yeah, I missed the pic too. It looks like you don't have the inner CVs. Is that correct? I see only the axles and the boot flanges.

Jeremy