Author Topic: Gearbox removal, does the engine have to come out?  (Read 2233 times)

Offline Gearbox

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As in the subject, can the gearbox be removed without the engine? Seen a few posts on the internet, some say yes and others no.
Any advice please, before I start taking mine out. (I have a replacement that I want to fit while I rebuild the existing unit)
Appreciate any advice

1957 GS with 1960 SR motor.

Online Black Sheep

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Re: Gearbox removal, does the engine have to come out?
« Reply #1 on: 10.08. 2021 17:48 »
No. Engine out for swinging arm machines and especially so for plungers where it is a bit challenging.
2 twins, 2 singles, lots of sheep

Offline berger

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Re: Gearbox removal, does the engine have to come out?
« Reply #2 on: 10.08. 2021 19:10 »
when i swapped mine for the rrt2 and then swapped it back yo the std the engine stayed in on my swinging arm model

Online muskrat

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Re: Gearbox removal, does the engine have to come out?
« Reply #3 on: 10.08. 2021 21:19 »
G'day Gearbox.
For swingarm models the box can be removed without the motor. With plunger models the whole lump has to come out, but in saying that the guts can be removed from the g/b shell with the whole lump in the frame.
Cheers
'51 A7 plunger, '57 A7SS racer now a A10CR, '78 XT500, '83 CB1100F, 88 HD FXST, 2000 CBR929RR ex Honda Australia Superbike .
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Online Black Sheep

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Re: Gearbox removal, does the engine have to come out?
« Reply #4 on: 10.08. 2021 21:42 »
I stand corrected. On the only occasions I have had the gearbox out, the engine came out as well.
2 twins, 2 singles, lots of sheep

Offline Ratchet Richard

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Re: Gearbox removal, does the engine have to come out?
« Reply #5 on: 10.08. 2021 22:00 »
Just removed and refitted my A7 gearbox.  It was quire easy once the primary inner cover was removed.  I found taking the top engine gearbox plates off helped a lot.

Offline Gearbox

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Re: Gearbox removal, does the engine have to come out?
« Reply #6 on: 10.08. 2021 22:27 »
Thank you gentlemen. Will have a go at pulling it out and leaving the engine undisturbed

1957 GS with 1960 SR motor.

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Re: Gearbox removal, does the engine have to come out?
« Reply #7 on: 11.08. 2021 10:19 »
G'day Gearbox.
What model do you have?
Would be great if everyone had their models in their profile (next to the flag). With about 1200 members it's a bit hard to remember who has what.
Cheers
'51 A7 plunger, '57 A7SS racer now a A10CR, '78 XT500, '83 CB1100F, 88 HD FXST, 2000 CBR929RR ex Honda Australia Superbike .
Australia
Muskys Plunger A7

Online Greybeard

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Re: Gearbox removal, does the engine have to come out?
« Reply #8 on: 11.08. 2021 10:41 »
Would be great if everyone had their models in their profile (next to the flag). With about 1200 members it's a bit hard to remember who has what.
Good idea. Make it so.
Greybeard (Neil)
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A Distinguished Gentleman Riding his 1955 Plunger Golden Flash

Offline Minto

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Re: Gearbox removal, does the engine have to come out?
« Reply #9 on: 11.08. 2021 11:06 »
Of course, some of you have more than just the one though so still helpful to specify in the post.
52 A10 plunger
Aprilia RSVR

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Re: Gearbox removal, does the engine have to come out?
« Reply #10 on: 11.08. 2021 12:46 »
G'day Fellas.
Without going off topic re bikes in your signature (profile).
 https://www.a7a10.net/forum/index.php?topic=419.0
Cheers
'51 A7 plunger, '57 A7SS racer now a A10CR, '78 XT500, '83 CB1100F, 88 HD FXST, 2000 CBR929RR ex Honda Australia Superbike .
Australia
Muskys Plunger A7

Offline Gearbox

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Re: Gearbox removal, does the engine have to come out?
« Reply #11 on: 11.08. 2021 13:00 »
Working on a Hybrid 1957 Gold Star with 1960 Super Rocket Engine.  Assume that the method of gearbox removal will be the same for a swinging arm A10

1957 GS with 1960 SR motor.

Offline berger

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Re: Gearbox removal, does the engine have to come out?
« Reply #12 on: 11.08. 2021 13:44 »
yes primary side off and plates off the gearbox, one plate can be left loose on the bolts/ studs

Offline Gearbox

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Re: Gearbox removal, does the engine have to come out?
« Reply #13 on: 12.08. 2021 08:09 »
Thank you again gentlemen. Hope to get it done today (assuming swmbo does not have other ideas)

1957 GS with 1960 SR motor.

Offline Gearbox

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Re: Gearbox removal, does the engine have to come out?
« Reply #14 on: 14.08. 2021 12:57 »
Well, after doing lots of house based jobs, finally got to look at the A10. Removed the primary side and taken all the bits off the gearbox. Hope to get back to it today.
Looking at various bits, I was wondering if the gearing was right. 23 tooth sprocket on the engine, 43 on the clutch, 19 on the gearbox and 42 on the rear wheel. Thought about putting a 24 tooth engine sprocket on.
When on the road, it was reading about 4000 rpm at 55 mph. Seemed low to me. Could be the rev counter is out or the speedo. The gearing is fixed, so as long as it is right, I know where to start.
Engine is to RGS spec, so assume I am best using RGS gearing. Fitting a Daytona spec gearbox if that changes anything

1957 GS with 1960 SR motor.