Printable Version | Subscribe | Add to Favourites
New Topic New Poll New Reply
Author: Subject: Prop to Sprocket adapter loose...??? Oooops
charlierevell

posted on 7/6/08 at 06:21 PM Reply With Quote
Prop to Sprocket adapter loose...??? Oooops

Anyone know why this would come loose? Just done my first run what you brung 1/8th of a mile and on the way home it started shaking like mad. Got back and the bolt had come out half way.

Seems like it was thread locked and the threads seem ok. So could the heat of the day let it loosen?

Can i just re thread lock it after cleaning and bolt it back together?

Anything special I need to do when tightening the prop bolts and the adapter bolts?

Fanx!

Oh... got 8.6 on the 1/8th.





Tango orange is an 'IN' colour!!

View User's Profile View All Posts By User U2U Member
bob tatt

posted on 7/6/08 at 06:31 PM Reply With Quote
i bought a indy with fire blade last year with a few problems sound car just needed fetteling one of the problems was a vibration above sixty thought some thing might have been out of line got it home gave it a good going over and it was only the prop to sprocket that was loose evidence of thread lock. then before the fitsr trackday this year i rechecked and it was loose again even thoigh they had lock nuts on them retightened them and i make a point of checking it before every track day now weird dont know what causes it anyone else had this problem....
View User's Profile View All Posts By User U2U Member
charlierevell

posted on 7/6/08 at 06:35 PM Reply With Quote
Well I wonder if its the heat the spindle gets up to then? It could be degrading the thread lock over time which is increased when very hot for long times (Drag racing etc.... )





Tango orange is an 'IN' colour!!

View User's Profile View All Posts By User U2U Member
bob tatt

posted on 7/6/08 at 06:45 PM Reply With Quote
im sure someone will be along very soon with an explanation just out of interest have you had any noise testing done on yours and what exhaust you running only asking as noise is becoming a real problem on track days
View User's Profile View All Posts By User U2U Member
charlierevell

posted on 7/6/08 at 06:56 PM Reply With Quote
Not had it tested yet, just waiting for my bro to get his audio software back on the Mac to check it.
Its been on track before tho, Im using the standard airbox and a remus can.
I've also got an add on sliencer tube to bolt on.





Tango orange is an 'IN' colour!!

View User's Profile View All Posts By User U2U Member
Hellfire

posted on 7/6/08 at 07:57 PM Reply With Quote
Charlie,

I must confess - we had a similar problem. You dont say who manufactured the adapter, what car you have or what engine you have.

When I posted this problem, the general response was that the friction between the prop flange and the adapter is enough to prevent the drive from transfering from the coupling to the 4 bolt shafts.

I was sceptical at the time and I still am. I personally think that the prop flange and adapter needs at least a couple of drive dogs or location pins to ensure the drive does not convert to the bolts.

The reason why it probably has come lose is due to the adapter and prop flange constantly placing torque directly onto the coupling therefore onto the bolts. They have stretched - plain and simple. As they come lose the friction obviously gets less placing more and more stress onto the bolts making them stretch more etc etc until they snap.

We had one bolt snap and all the other three were lose before we noticed! We have replaced them all but we watch them like the proverbial hawk now. I think it is a design flaw personally but thats only my opinion.

Steve






View User's Profile Visit User's Homepage View All Posts By User U2U Member
ChrisGamlin

posted on 7/6/08 at 09:01 PM Reply With Quote
Steve, I read it as the bolt holding the prop adapter to the output shaft had come loose, rather than the prop bolts themselves?

A good threadlock should hold it as it does on the bike, but make sure that its actually clamping tight against the prop adapter and the adapter isn't thinner than the depth of the output shaft splines, meaning it slides a little. A lot of prop adapter manufacturers supply a shim with it to ensure the bolt clamps down onto the adapter rather than just bottoming out tight against the output shaft.

[Edited on 7/6/08 by ChrisGamlin]






View User's Profile E-Mail User View All Posts By User U2U Member
eznfrank

posted on 7/6/08 at 09:23 PM Reply With Quote
On some of the bike engines they have a retaining washer, which folds over one side of the nut. When I got my adaptor it was machined so that I could not get the washer on. I checked with the supplier and they suggested some high strength line lock. I've not had the car running but it's one of those things I shall be keeping a very close eye on.
View User's Profile View All Posts By User U2U Member
charlierevell

posted on 7/6/08 at 10:21 PM Reply With Quote
Well... Had it all apart now.
Its an MK Indy with a 954 03 Blade engine. Not sure who made the prop adapter.

The adapter had come loose, the 4 flange bolts were fine, they were bloooody tight!

Its the main bolt that bolts the adapter on that was the problem, it had just worked loose, I wonder wether the washer going concave had something to do with it.

That or the loctite dying!
I've loctited it all back up, marking on the prop bolts to see if they loosen.
All seems good now, so will have to take it for a spin and see what it does.





Tango orange is an 'IN' colour!!

View User's Profile View All Posts By User U2U Member
worX

posted on 8/6/08 at 05:10 AM Reply With Quote
Charlie,

Not that you haven't already! but if you read ChrisGamlin's post it may go some way to explain it.

The first time I fitted the prop adaptor, there was some fore and aft play on the shaft, but I was told that would be ok. I didn't like the sound of that, so I machined a washer up to take up the slack and never had a problem with that particular bolt.

It's worth checking with the prop disconnected that you don't have any play whatsoever in there.

Cheers,
Steve






View User's Profile Visit User's Homepage View All Posts By User U2U Member
charlierevell

posted on 8/6/08 at 09:11 AM Reply With Quote
Hiya steve, Yeah looked at Chris's post and checked it. Liam seems to have put a spacer in there as It locks up real tight and was locked up tight until it came loose.
Having done it back up again it still locks tight to the splines with only a slight (tiny tiny) amount of play but i think thats in the gearbox shaft.





Tango orange is an 'IN' colour!!

View User's Profile View All Posts By User U2U Member
Avoneer

posted on 27/9/08 at 03:01 PM Reply With Quote
If the washer concaved, it's not thick enough and will do the same again.

Pat...





No trees were killed in the sending of this message.
However a large number of electrons were terribly inconvenienced.

View User's Profile E-Mail User Visit User's Homepage View All Posts By User U2U Member
Toady1

posted on 30/9/08 at 10:22 AM Reply With Quote
Hi Charlie, the prop adapter is a westfield one. Yes it was loctited in, and came loose on me once on a trackday too! Maybe 2 nuts one to lock the first one if there is room? I cant remember.

As for noise, it was around 103dB without the add on silencer, around 98 with it.

View User's Profile E-Mail User View All Posts By User U2U Member
Andy W

posted on 30/9/08 at 04:03 PM Reply With Quote
On my MNR build the adapter was to wide to allow the fitting of the locking tab washer, I had to have 2.5mm machined off the back of the adapter to allow me to use the tab washer. As far as I know all bikes have tab washers on the sprocket nut, and I wouldn't be happy without one.

Andy

View User's Profile View All Posts By User U2U Member

New Topic New Poll New Reply


go to top






Website design and SEO by Studio Montage

All content © 2001-16 LocostBuilders. Reproduction prohibited
Opinions expressed in public posts are those of the author and do not necessarily represent
the views of other users or any member of the LocostBuilders team.
Running XMB 1.8 Partagium [© 2002 XMB Group] on Apache under CentOS Linux
Founded, built and operated by ChrisW.