MGB Roadmaster

[donfaber]

Roadmaster to be shown at MGC in Indy? Can't find any details of meeting on-line - where/when (I live in Columbus, IN)?

[mowog1]

Don....we are at the Clarion Waterfront just off the intersection of I-465 and I-74 on the west side.

Most of the information has been posted on the MG Experience MGC Forum.

The guys are out on self-guided tours of Parke County, IN today.

We'll be at the Union Jack Pub in Speedway tonight.

Tomorrow morning about 10:30am we will be a Ray Skillman collector cars in Greenwood, IN

Tech sessions tomorrow afternoon at the hotel.

Saturday morning is car display/show at the indianapolis Motor Speedway Museum from 9am to noon....then to downtown Speedway for lunch and a tour/indycar experience at the Dallara Indycar Chassis factory.

Saturday evening is banquet, awards, and auction at the hotel.

Come on out!

[mowog1]

I'll look at some different gauge sets and get some prices.

I personally do not like the calibration of the Stuart-Warner gauges, especially the speedometer.

I'll take a look at Speedhut and Autometer.

[mowog1]

Well...the tradition continues.

I've not been able to get under the car yet....

...but my guess is one of the universals on the differential is FUBAR.

[mowog1]

OK...it is NOT a universal.

Take a look at the coil-over.

[Dan B]

What could cause that?  How does the one on the other side look?

[MGBV8]

Broke the shock? Hope the axle is okay!

[madmax]

<sigh>    

Guzman has explained the coil over ("spring too short"-- it was cranked up the adjustment quite a bit, as you can see in the pic!)

But I'm more curious about the Steering Wheel!   How the Hell does THAT happen?!?     Cheap chinese crap meets vibrating steering wheel and operator who clenches?!

<sigh>

M

[mowog1]

Max....that steering wheel has wobbled from day one. I remember it doing that on the Power Tour. I believe it broke at the outer rim...then the flex caused the stress fractures at the hub,

We've had a lot of folks in the driver's seat, many who use the sterring wheel to push themselves out of the car. (Same as the fatal error some commit by pulling themselves out of a tourer by grasping an pulling on the windscreen!)

Carl....I agree...but we won't know much until later when we can get under the car and take a better look. Hopefully, the "shiny bits" are just that...."shinty bits".

Lloyd Faust has given some good advise...."Ricki...remove the shock on the other side and take the spring off of it. Then reinstall the shock and move the suspension up and down by hand....make sure it doesn't bind in any position."

Obla-di, obla da.....

[BlownMGB-V8]

That's pretty ugly. Glad it didn't cause any sort of mishap. I believe those are 8" springs and probably around 300 or 350 rate. Perhaps a 10" or even 12" would be better, someone else will have to advise on that. I'm no expert on coil-over units. Be sure to have a good look at the top mount though. It doesn't look like that was the failure point from the photo but the bolt is in single shear so check it out if you don't mind.

I also noticed the wheel didn't feel real solid in Omaha. Never expected it to break though. The car seems to be getting a pretty good thrashing which really, is a good thing. We are learning things from it that we would not otherwise know. Now I do not recall where we got the wheel, if it was VB or ebay or where. -- OK I went back and looked. Page 73 about 1/2 to 2/3 down. Bill Young bought a new wheel for us, I think he got it from Moss Motors. It was installed in early December 2011. Anybody else think that could be a warranty issue?

Jim

[mowog1]

The Roadmaster is now safely stored in Indianapolis at Dave Kirkman's house.

Post-mortem of the failure will have to wait a bit. Still cannot see the upper portion of the rear member/coil over assembly.

In addition to this failure and the steering wheel failure....the barrel to the driver's door lock fell out of the assemby (and is safe inside the console) and the cigar lighter works sporadically at best. (My GPS would power down quite frequently.

Obla-di, obla-da.

[mowog1]

Received a new sending unit for the fuel tank of the Roadmaster today, courtesy of Curtis Jacobsen. THANK YOU!!!  Maybe this will correct the reading of the fuel gauge and eliminate the close calls/near misses/actual incidents of running out of fuel.

I'll take it over to indianapolis to add to the Roadmaster parts-to-be-installed/repaired.

I wonder if we should make the effort to get the Roadmaster back down to Jim's to evaluate/repair the rear suspension as it was he who made the original design and is most familiar with it?!

I also learned that the Roadmaster has a fly-away hand brake....it's very frustrating to attempt to release the hand brake in a conventional manner when one of these prawls are installed. Please advise all drivers/caretakers of the Roadmaster of this installation when handing over the keys. (I had never driven a car with a fly-away hand brake...it was very frustrating until I learned what was going on......)

[BlownMGB-V8]

Sorry about the brake Rick, I thought by now everyone knew about it. Could indeed be frustrating, but could be handy for some on uphill starts I suppose. Not that you'd have that issue...

Re: rear suspension, maybe first we need to know what we are dealing with. If it's just a broken coil-over that should be easily replaced and the car is back in service. I am no authority on coil-over units so if it is thought that something needs changed there such as longer springs as Bill G has advised, I would recommend conferring with Ted Lathrop as he knows more about them than anyone else I am familiar with and if we need longer springs he can get them from his regular supplier. If he agrees with Bill then I'd say that would be something we should do.

There was no binding in the suspension as built and installed and aside from the guys shortening the adjustment of the forward strut to bring in the alignment there still should be none. But I suppose we could look at that. I don't see how that could break the shock though. I think replacing the shock first so the car can be driven ought to be the first step. Then if you or Dave wants to drive it over we can take a look.

[BlownMGB-V8]

Hey guys, a thought just occurred to me. The eye of that shock is threaded and screws on to the shock rod, right? So what happens if the rod screws back out of the eye? If that happens doesn't it do just what this one did? I wonder if maybe they forgot to put the locktite in the threads before it went together. If that happened then it could be that all we need to do is thread the pieces back together (with a generous application of locktite of course) and reinstall the shock.

I'm not saying it will be just that easy, but certainly it seems like a possibility. Just think. you could be the hero that finds the easy fix! ;-)

Jim

[mowog1]

To be honest, Jim, that was my first thought.

But I could not see under the car enough to see what was going on with the top of the unit.

It's going to be a couple of weeks before I can get over to Indianapolis to see what's going on.

[BlownMGB-V8]

Great minds think alike? Just that some of us are a little slower ;-)

Jim

[Moderator]

thread the pieces back together (with a generous application of locktite of course)

Jam nut, perhaps?

[madmax]

Guys:

That IS a very short spring, there is lots of adjustment to bring the base down.   Maybe lighter weight 12" springs would be best?

I don't think the rod screwed out of the eyelet-- wouldn't the spring have shot out?   The fact that it's all there but "bent" makes me think the shock rod bent rather than disassembled.  

$.02

M

[BlownMGB-V8]

Max, if memory serves I believe those are 350 lb springs and the rate is about right. Could be a little stiffer maybe but lighter would probably not be a good thing. Longer springs would have less of a progressive rate I would expect, in essence almost the same thing as a lower rate. So going to a 10 or 12" spring (depending on how much adjustment there is now) I'd be inclined to go up another 25 lbs on the rate. I don't think it'd hurt the ride noticeably.

But again, I have very little experience with coil-overs and I'm anything but an authority on them. The good thing is that the springs are not particularly expensive.

Jim

[mgb260]

Jim B, 350lb is 350lb rate tested, regardless of length. If you have  the same diameter wire and cut 4" off a 12" spring you would be correct. Less coils for the same diameter wire is stiffer. My guess is the 12" spring rated at 350 will have either thicker wire or stiffer spring to develop the same rating. I agree that will be about right for the rear. 450-500lb would be about right for front coilovers depending on engine weight or preferred stiffer handling(and distance of shock to the wheel). I have a theory that the spring being too short when the wheel is in droop and when it came down hard broke the shaft. I recall you said the Roadmaster had 6" of travel, you need approximately a 12" spring. If 5" travel a 10"spring. The Mustang II Front suspension uses a real short shock and at best has 3 1/2" total travel so a 7"spring would be ideal. MGB common rear  tube shock conversion has 5" travel so with same mounting distances  would use a 10" spring. An inch one way or other probably won't matter.

[mowog1]

This is very helpful information. Thank you!

[BlownMGB-V8]

Thanks Jim. The shocks are at a 2:1 ratio with wheel travel, which is 8" so shock travel is 4" and spring length is 8". I think that falls inside those guidelines, so I'm not sure we are any closer to figuring out why it failed. Could we be at coil bind? I have no idea.

What I meant above is that the progressive rate on a shorter spring will be higher than it is with a longer version of the same spring. In other words, with any spring pressure will increase as the spring compresses. You can take two springs that start off at the same pressure, one short and one long, and as you compress them the shorter one will get stiffer faster. So the same spring only made longer would need to be made with thicker wire in order to avoid bottoming out the shock. Maybe that means the rate is the same. I guess if you are going from tested compression and pressure figures it would, and if that is how coil-over springs are rated the 350 lb/in springs in a longer one should be fine. But 25 lbs stiffer wouldn't do any harm either. If coil bind is the issue than longer springs should cure it. I have moved my car back over to the lift bay so I'll raise it back up and take some measurements to see if coil bind could be a problem.

Jim

[mgb260]

Jim B and Rick, If you jacked up the spring too much to increase road height you could be at coil bind. I have experience with Pro street parallel 4 bar set ups and long travel off road buggies.Another problem may be initial shock setup length. Normally I have setup my shock length to be slightly higher than mid point travel at road height desired. For example if you had 6" travel I would set the shock length at the 3 1/2" level at desired road height. Hope the info helps.

[BlownMGB-V8]

Most of the wheel travel is in the downward direction from ride height so the shock would definitely be compressed beyond the midpoint normally. I'd say the travel is probably somewhere between the center and around 3" up and 5" down so at the shock, between 2 : 2 and 1.5 : 2.5 depending on the ride height. That should be OK, right?

I took some measurements on mine and got .7" between the coils, 8 spaces, .444" wire. That should give 5.6" of travel but again, depending on the ride height adjustment. My car sits kinda high right now but the RMs could have been adjusted up further. Over an inch and a half further I sort of doubt but I can't say for sure. It's had a lot more miles on it.

It also has rubber bump stops fitted inside the top of the springs which means there should have been no sudden banging at the end of travel.

Jim

[mgb260]

Could just be a faulty shock or top bracket broke. I've used Chassis Engineering or Morrison rear set ups that used a standard shock(usually Gabriel adjustable) and QA1 coil overs. What brand are those?