'74 750GT First gear pops out

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Styles52
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'74 750GT First gear pops out

Post by Styles52 » Tue Oct 22, 2013 11:59 am

Recently acquired a '74 750GT w/6500 miles, that occasionally pops out of first gear, but only first. Have not pulled the cover off yet, hoping it could be as simple as a broken selector spring. Having trouble locating one, part# 0150.49.010. Modern Ducati dealers don't show the number available anymore, wondering if someone has any other options or places to try. Thanks, Jack

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geodoc
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Re: '74 750GT First gear pops out

Post by geodoc » Wed Oct 23, 2013 8:19 am

Styles52 wrote:Recently acquired a '74 750GT w/6500 miles, that occasionally pops out of first gear, but only first. Have not pulled the cover off yet, hoping it could be as simple as a broken selector spring. Having trouble locating one, part# 0150.49.010. Modern Ducati dealers don't show the number available anymore, wondering if someone has any other options or places to try. Thanks, Jack
Heh Jack,

Wouldn't think that the detent spring would be the cause. Normally, they just do their job and pretty much never wear out. The shift cam should be like new at that mileage. Same with shift return spring. Still, with the practice of troubleshooting trying the easiest, cheapest things first, taking the shifter box apart looking for worn or broken stuff is a good first step. I'm afraid if it's popping out of gear like you say, it's more likely some speed-shifting previous owner that rounded off the engagement dogs and a case-splitting is in your future.

G

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Re: '74 750GT First gear pops out

Post by BevHevSteve » Wed Oct 23, 2013 10:57 am

Please do not double post (post the same question in 2 places). I deleted your other post.

This is the one you need

Image

We have em in stock of course..

https://store.bevelheaven.com/engine-re ... s-to-1978/
Image
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Styles52
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Re: '74 750GT First gear pops out

Post by Styles52 » Wed Oct 23, 2013 1:16 pm

Thanks for the replies, and sorry Steve for double posting. It was only after looking closer, I realized it was in the wrong section.
So yes, I am going the simple way first, I have the cover/selector assy. off and sent it to a friend/shop who has some experience with them. I'll know tomorrow if it's an easy fix, or as you mentioned having to split the case.

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Re: '74 750GT First gear pops out

Post by BevHevSteve » Wed Oct 23, 2013 1:17 pm

the spring above is in the selector box. No splitting cases to replace it.
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Steve Foster
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Re: '74 750GT First gear pops out

Post by Steve Foster » Fri Oct 25, 2013 5:01 pm

Styles52,

I have experienced the same issue with my 750 GT jumping out of first gear. It's happened on at least two occasions, at approx 30,000kms intervals. The solution was the same in both cases so it has been well tested by me. See the topic "first gear slippage" in the "Engine &Transmission Shop" section. viewtopic.php?f=50&t=1123

If the detente spring breaks it can result in jumping out of first gear. And they do break. Part no. 0150.49.010 (the selector spring shown in Steve's post is 0400.130.110 - I've never had one of those break). Get a couple of spares. Quite easy to repair but take a good look at the selector mechanism when disassembling (I take plenty of photos with a digital camera for reference). Getting the selector spring in the right place when reassembling can be a bit fiddly but I always manage it in the end somehow.

Cheers
Steve.
1974 Ducati 750 GT

machten
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Re: '74 750GT First gear pops out

Post by machten » Sat Oct 26, 2013 5:10 am

Quite easy to repair but take a good look at the selector mechanism when disassembling (I take plenty of photos with a digital camera for reference).
Couldn't agree more. If you haven't put one togther before, it might take a bit to get your head around the first time unless you take some photos after removing the inside cover whilst trying to keep everything in place.
Getting the selector spring in the right place when reassembling can be a bit fiddly
Mr Foster is speaking with understatement only made possible by experiencing some bloody fingers and searching under the bench for the detent ball bearing! ;)
the selector spring shown in Steve's post is 0400.130.110 - I've never had one of those break
I've a had few break, the most recent a few weeks ago on my Sport, so I'm taking the opportunity to refurbish the selector by fitting some new bushes and a selector fork if required - both these (outside of poor adjustment) are the major contributors to poor detent selection. It's worth checking that out if you're in there anyway.

Image

Kev

Styles52
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Re: '74 750GT First gear pops out

Post by Styles52 » Sat Oct 26, 2013 5:04 pm

Although I was hoping to find something glaringly wrong, everything appeared ok when the selector cover mechanism was opened up. So, cleaned,lubed and adjusted, I'll have it back in a day and re-install and see where I'm at now. Thanks for all who have posted.

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Re: '74 750GT First gear pops out

Post by abmartin » Sun Oct 27, 2013 6:28 am

The selector spring doesn't have to be broken to cause poor gear selection. A weak one will cause the same problem. The spring should be replaced as a matter of course. Worst case with a broken spring is that you can't select any gear or the gearbox can't be shifted out of the gear it was in when the spring broke.

Bruce
1979 900SS
Fredericton, NB
Canada

Styles52
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Re: '74 750GT First gear pops out

Post by Styles52 » Sun Apr 20, 2014 8:14 pm

Final update: Although the springs looked fine and not broken, over the winter had a new detent spring and shift return spring installed, and just now able to ride. Success!, so far it shifts fine and does not pop out. It did have the experience as if the clutch lever was pulled in for a split second, (as experienced by another poster), but clearly a fresh detent spring was enough to solve the popping out of gear situation function and save having the cases opened up. Thanks to Steve from BH and Steve F. from Australia for their help in locating parts.

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Re: '74 750GT First gear pops out

Post by mike75 » Wed Aug 19, 2015 9:27 am

This is the one you need

Image

We have em in stock of course..

https://store.bevelheaven.com/engine-re ... s-to-1978/[/quote]

Do you still have these, I fear I may be in need of one and the link no longer works
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BevHevSteve
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Re: '74 750GT First gear pops out

Post by BevHevSteve » Wed Aug 19, 2015 11:35 pm

https://store.bevelheaven.com/Engine-Re ... s-to-1978/

Sorry, made some changes to my database and some category names got changed. The above link should work.
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