DIY propshaft?
 

as most of you know i,m building on a tight budget so would like to ask your opinion on whether i should or should not fabricate my own propshaft for my Roadster from the donor propshaft?

it looks fairly easy to do but am i being too tight to buy one or is it not safe to fabricate one from the donor parts i have?

£100 approx for a new propshaft compared to £0 for a diy one, the money i could save would pay for other parts i still need but if its a safety issue then i,ll accept that ,

so your opinions/advice is welcomed & sought.

thanks
andy:)

TBH it is what they advocated in the Champion book, and it is mentioned in the roadster.

It all depends how confident you are with your welding, and if you can get the right materials, although I am assuming the propshaft needs to be shortened (no donor)

You could always take it somewhere and have it checked afterwards, and maybe balanced.

If you are really worried, but intent on doing it, why not fit a safety loop? The yanks do it quite a lot on drag cars

http://home.fuse.net/fastmonte/DSSL4Gbodies.htm

I just googled "prop shaft safety loop" and that was the first thing to come up.


I'm sure someone will be along soon to say "its a dumb/crazy/stupid idea" but then again so is building a car from scratch:D

Sean

Hi Andy,
I'm making my own, I was given a 2.0l pinto from a transit and it came with g/box and prop the best bit is the transit prop has servicable joints so im making my own also the transit spline is the same as for a type 9 and the rear flange fits my 7.5" sierra diff
I just have to decide whether to use the big tube or the small tube which has the centre bearing
just to say I've modified props before and never had any probs.
just make sure it runs true before final welding and that the joints line up with each other
Ray:)

cheers Sean/Ray,
so i,m not barking mad ???:D

as the donor prop i have has a center joint which obviously i don,t need to incorporate into the shortened version would i still need the coupling at the gearbox end?
would it be ok to have the splined end a "rigid end" & the diff end with the coupling thats already there? the reason i ask is this would make it alot easier to fabricate as someone has suggested to me to just use the splined end welded onto the main shaft once i get the dimensions spot on :confused:

i feel confident enough to make it run "true" & would also sleeve the join to ensure a strong welded section,
like you say it is mentioned in both books so folk must have done it in the past:cool: , its not just the fact that i,m a tight git :o

i like the idea of a safety loop, think thats a good idea regardless of a diy prop or commercially made one.

cheers
andy

I made my own propshaft as well.
Including the rubber donut at the front.

I was not entirly happy with it, thought I would change it later.
That was 3,000 miles ago.
Still going fine, think I'll keep it...:D

David

thanks Adrian,
the safety factor is my main concern, tho i wasn,t thinking of using the rubber ring as like you say it is rather large for the tunnel,
some fellow kit car owner has suggested that i cut the splined end off the current prop & friction fit it into the larger tube that has the diff flange & weld it up once all is true, tho if i still need a coupling at both ends i could cut/shut the two parts(pipe) & then sleeve the joint, hmmmmm:confused:

Dogwood...... do you have a photo of your installed prop please, pref showing the gearbox end & the joint you made to fabricate it please?

thanks
andy

I'll be setting mine up in the lathe & welding it up ;)

That bloody rubber donut is a very tight fit in the tunnel though :eek:

Hoping to find an early model prop before I get to that stage.

Cheers for the tip Ray, I may very well be able to lay my hands on an early Transit propshaft :cool:

I would say you need a joint or donut at the g/box end and a joint at the rear
Ray:)

Sorry Andy mate.
Just checked, Thats one pic I ain't got.
If it ain't pissing hard tomorrow I'll get the car out and take one.

As for the joint, I cut the donut end off.
Then put it in the lathe to give me the shoulder to reweld the pipe back on.

Hope this little pic helps


David

HI
I made my own prop. It has a UJ a each end. Having coverd over 4000 miles and driven the car hard on track days im happy with its performance.

thanks David, yes that diagram does help, yes please to a pic as long as you don,t get wet :eek:

i,ll give it a go tomorrow, if it works then great as my wallet can breathe a sigh of relief for a little longer:o :D

thanks everyone for your input, much appreciated.

cheers
andy

Andy.
Can you send me a PM tomorrow to remind me.
Coz I'm bound to forget.

Yea, Yea...Alright so I've had a sherbert or two ok...:rolleyes:

David

:D no prob, & thanks :cool:

andy

Place in Team Valley can balance it for you !

For those looking for a way to lose the huge rubber "do-nut":

I put a gearbox from a sierra into my old cortina many many moons ago. Found the cortina yoke didn't fit the sierra box, so went back to the scrappy with the box and raided his propshaft collection. Found that the yoke from a hilman vogue fitted the sierra box in terms of the splines, just needed to be shortened by about an inch. Even the UJ's matched.

Back to the original question, if you get it lined up properly and your welding is good there should be no problem except possibly/probably balancing.

Andy
100% agree with all these guys
a flexible joint at both ends is a must and diy props are achievable
you just got to weld it true
and an old trick for when its on the car
if you have a slight vibration put a jubilee clip around the shaft and run it .if no better rotate it slightly etc etc until the vibration goes i have seen up to three jubilee clips used to smooth out a vibration :eek:
cheers les g

PS. it wasn,t my welding LOL :D

I made mine, it's fine. Rubber donut fits easy in a chassis made for an MT75 'box.

Neil

Good - because that's what I'm planning on using.

Is there plenty of room for brake and fule lines, plus the leccy??

Sean

Hi Andy
Pic's as requested....








HTH David

I can't believe that that Andy made you take the top off of your tunnel for that photo. :D

Looks a propper job David ( Excuse the cheap pun ) :o

Given me a clue to the way forward that's for shure ;) :)

thanks everyone, sorry for late reply but have had major internet connection problems, now sorted by ME :D me & computers don,t usually get on.

thanks for your help with the propshaft idea,

Les G i like the idea of the balance weights :cool:

David, thanks for the pics , they really help, clears a few things up.
i,m going to give it a go.

so thanks for all the input.

cheers
andy:)

i was going to make my own shaft but my rubber donut thing is all split and falling appart. i am going to take the plunge and just buy a new custom one as i know it will have to take some serious abuse with me behind the wheel :D

Yea I know, pain ain't he...:D

Actualy it was not a bother, coz I wanted to check out the donun anyway.
( You ain't the only one that drives like a loon Ash :eek: )

Also part of my rebuild is to lower and move forward the handbreak leaver.
I wanted to see how easy it would be.

David

:o
tell you what !!!!!

i,ll buy the donuts at stoneleigh next year :p the ones with sugar on tho :D

thanks for the help

andy

have you ever had an Eureka moment???????:D

well today whilst fabricating my own propshaft i was taking the center bearing housing apart to make the whole donor prop easier to handle,
after i,d got the center bearing apart i was left with the metal housing that holds the rubber vibration bush in place, so i took the rubber out of it & this now leaves me with in my opinion the perfect safety hoop for the prop,
i placed it onto the tranny tunnel tubes & raised it up on some 25mm sq tube that i had spare & lo & behold its a perfect fit, it allows the prop to rotate freely with enough space for slight movement at the gearbox end but in the event of prop failure it,ll stop the prop from coming thru the tunnel wall or dropping thru the floor, anyone see a prob using this?

cheers
andy:D

Erm...... can you still get the prop shaft on and off??:eek:
Does the UJ go through it, or does it unbolt?

David

Ohhh Nooo
 

I try not to have Eureka moments.

Only ever had Two, both resulted in the arrival of my lads :D :D

Can't get a handle of your idea Andy :o

Afraid my brain is a bit FUBAR after the last week or so :eek:

sorry had laptop prob, sorry for delay in reply,

i,ll try to explain a bit more clearly,
the hoop that originally held the center bearing on the donor prop, i,ve dismantled the bearing & removed the rubber internal bush, cut the bottom off the metal housing which now creates a safety hoop that i can bolt down onto the tranny tunnel frame,

maybe i should take a photo tomorrow? :o

andy

Yea, think I got it now....
Had visions of you welding it all inplace then thinking.
How the fug am I going to get the prop on...:D :D :D

:D David ...... oh come on, i know i,m not the sharpest knife in the drawer but even i wouldn,t have done that :eek: ;) :D

as for the hoop, its a simple solution & its free, now you know i like lo-cost .

it works too.


andy

No offence.....:D
But......
I could defo imagine ME doing it though....:rolleyes:
I have been hit with the "Stupid stick" a few times

non taken buddy :D

me & the stupid stick are good mates some days:o

andy

I think a prop safety loop is an excellent idea I saw an american guys locost blog a while ago and he had made a 2 piece loop from something like 3mm x 30mm strip.
Definatley could save damage to the car and your legs if the prop let go.
Am guessing the prop would just fall into the loop like a crude bearing if it snapped and help stop the prop whipping around.

Do you need at least 2 for it to be worthwhile? Could see that if it broke you would have both the diff and the engine ends spinning when rolling.

i plan on putting the safety hoop just forward of the TT6 uprights as this then creates quite a good cage around the prop using the TT6 & TT4 uprights as additional structures to stop the prop coming thru the tunnel into the cockpit.

cheers
andy:)

10 Points Andy,bloody good idea 100% no cost too,if you are really concerned why not beef up that part of the tranny tunnel with a cross brace and a sheet of ally near the joint. I think I will do it now as that's where I am welding in now.

:) cheers Paul,
its not very often i have a good idea but this is one that might be of use to others.
i can,t put any more braces into the tranny tunnel as i have fitted the floor now, but this safety hoop is defo going in. :o :cool:

andy

Andy
that is a really good safety feature you are talking about
Jonneturbo lost his car to a fire when the prop failed and ripped out his
fuel lines in the tunnel
cheers les g

cheers Les, credit should go to Londonsean69 for the idea in the first place, i,ve just taken it on & found a locost solution,
hope it is of use to others too.
i,m only using thin ali for my tunnel sides so any extra protection from a failing prop is welcomed, its even better knowing that it was free,
i mean after all i HAVE to keep my reputation for being a tight git :o :D

cheers
andy

Think I may be doing the same...
Just read this on LCB

"Another propshaft failure
Not mine,on a Seven that Dave Walker had on his rollers, went through the side panels and hit his leg at 120mph On page 98 in this months PPC.
That does it for me, definitely going to reinforce the tunnel."

http://www.locostbuilders.co.uk/view...php?tid=122181


David

wow, that sounds nasty, i haven,t read the article so hope the guy is ok.
strange how this thread has discussed the very possibility of that happening, scary thought :eek:

lets hope it doesn,t happen to anyone else.

cheers
andy