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Question on ZB propeller shaft clearance

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mcquaid Avatar
mcquaid jim jans
hood river OR, USA   USA
I installed the custom drive line and finished the mounting plate for the Datsun transmission. I do have one question though; is there enough clearance for the propeller shaft in the photo attached, or is there a chance of rubbing? The clearance between the bracket and the shaft could be increased a bit with an additional spacer plate between the transmission and the mounting plate. Recommendations?

I have also pumped in break-in oil using a small hand pump in order to make sure all the internal parts are lubricated. But I noticed the four nuts on the rocker towers are missing, so I’m wondering whether or not the machine shop tightened down all the other nuts correctly and just forget these last four nuts, or what? Further investigation to follow.


Jim Jans
'58 ZB
Hood River, OR

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johnbeesley Avatar
johnbeesley john beesley
Berkhamsted, UK   GBR
Not enough clearance, I`m afraid !
Have a look at the web site:- magnette.org. This being the MGCC official Magnette register site.
Then select "Tech Tips" next "modifications" finally "gearbox"
The notes regarding how to increase prop shaft clearance are worth a look, a simple mod that solves the problem.
Regards.
John Beesley

mcquaid Avatar
mcquaid jim jans
hood river OR, USA   USA
John: I was afraid of that. It's been years since the original drive line was installed and I never took any photos back then. I'll check out that web site: magnette.org

Thanks

Jim

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enigmas Avatar
enigmas Vince Stok
Melbourne, Victoria, Australia   AUS
Jim Jams...I'd be having a discussion with the machine shop and whoever built the engine. Definitely not good, not good at any level! I had a similar case many years ago with a 6 cyl Triumph PI engine....the crankshaft thrust bearings fell out and the crankshaft scored the block thrust faces. As well, 2 bolts were loose in the timing case and ready to fall and mix it with the camshaft timing gears. This was on a fully rebuilt engine with minimal miles on it. Last time I ever had anyone assemble an engine for me.
Leaving the main support bolts off the rocker gear pedestals is a gross error that could have caused a lot of damage. God only knows what else was left off, undone or poorly assembled...including bearing clearances. Unfortunately now...if it were mine, I'd want to check it out thoroughly... and that's an engine out on the bench task.



Edited 1 time(s). Last edit at 2017-12-07 05:59 AM by enigmas.

MGwrench Avatar
MGwrench John Perkins
Wildwood, MO, USA   USA
Vince: I agree with you completely, particularly when I can see in the photograph that is appears the shop did not use the correct nuts for the head studs and one of the studs holding the rocker assembly appears to be too short. I would want to disassemble that engine and check every dimension and all of the fasteners.

simon8 Avatar
simon8 Simon Beyertt
Rothenstein, Thuringia, Germany   DEU
and remember to put on the special washer that locks the oil-hole plug, left in your picture...
Simon

mcquaid Avatar
mcquaid jim jans
hood river OR, USA   USA
John: I have 11 nuts on the head that use a 9/16 socket and 4 nuts that use a 1/2 socket on the rocker towers, which nut seems to be wrong? The nut on the # 1 cylinder far side fits a bit tighter using a 9/16 socket but a 14 mm fits a bit better maybe due to a rough edge on the nut itself. This machine shop has been a pain from the start, I made the mistake of telling them, " they can take their time" 22 months ago because I went in for a hip replacement 17 months ago. Thinking they would be finished when I got back on my feet, wrong! I had to pick up the engine from them back in April of this year because I was running out of time with summer fast approaching. They had said it was all set except for the timing gears and timing chain cover due to a missing gasket. So I finished up that task. I am with the understanding that the two short rocker studs are normal (inner) and the two taller (outer) rocker stud are for the valve cover nuts.

Simom: I have attached a photo, is that special nut on the rear tower?

Please let me know if I need to make any corrections, the engine is going together slowly but I am making progress.

Thanks again

Jim Jans
'58 ZB
Hood River, OR



Edited 1 time(s). Last edit at 2017-12-07 10:07 PM by mcquaid.

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paddyreardon Avatar
paddyreardon Paddy Reardon
Calne, Wiltshire., UK   GBR
1933 Morris Minor "Evie"
1956 MG Magnette ZA
Hi Jim,

You may, or may not have a clearance problem. The prop shaft can only strike the gusset bracket in rebound. I.E. when the suspension is at the maximum down position. This is defined by the maximum length of the shock absorbers. If you have the car supported on it's body in the photograph, the axle will be as low as it can go. Allowing for 1/4" more clearance, you will probably be OK. If the car is supported on the axle, you have a problem.

I ran into the same issue with my Type 9 conversion. After a lot of fiddling around, I installed MGB lowering blocks on the rear axle. This moved the axle upwards in relation to the lowest possible position the springs will allow, increasing the clearance at the gusset. I used 1" blocks, but I'm pretty sure 1/2" would work as well.

Paddy

simon8 Avatar
simon8 Simon Beyertt
Rothenstein, Thuringia, Germany   DEU
Hello Jim,
I meant the "washer" shown in the pictures...
Simon

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mcquaid Avatar
mcquaid jim jans
hood river OR, USA   USA
Simon: Back to the drawing board. I do not see that special washer in my pile of extra parts, I guess its back to the machine shop to see what happen to them?.

Paddy: The ZB was sitting on blocks, so I guess I'll have to make some modifications from the magnette.org site to the cross member support and adjust the transmission mounting plate to get a bit more space between the propeller shaft and the cross member.



Thank you all for your help.


Jim Jans
'58 ZB
Hood River, OR

MGwrench Avatar
MGwrench John Perkins
Wildwood, MO, USA   USA
Jim: In the photos of your engine, the eleven studs that have 3/8x24 threads normally have 10 nuts that are taller than a standard hardware store nut and one that is a double nut for the steady bracket for your air cleaner. The double nut is there, but some of the other nuts appear to be the hardware store variety. It could be a trick of the picture. But Simon is correct about the special washer that goes under one of the 5/16x24 nuts for the rocker stands.

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