Lay shaft pinion not meshed correctly

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Loonynino

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Hi, im new to the website. Just bought a 2nd hand FG marder to try out 1/5 scale as i always been a electric rc man. It came stock with a 23cc engine, looked pretty clean under the shell. Been in storage for a year. It started no problem and ran good.

I then started doing some reading on here and decided to check mine out in more detail. At first noticed spur and pinion were well used so ordered some replacements and upgrades.

Alloy 18t pinion and steel 16t pinion.
Plastic 46t and 48t spurs.

Then noticed on a second run quite a lot of metal noises when running. Upom inspection after bash, thats when i saw that there was a lot of metal shavings under lay shaft and diff. The layshaft pinion is sitting quite far from diff and also only half way out on horizontal contact, if you know what i mean.
I can see that top of the teeth on the 16t pinion had become pointy and narrow, i think thats where the metal shavings are coming from. Diff looks ok.

At the moment gears are:
18t pinion and 46t spur
16t lay shaft pinion and 48t diff.
:(
 
Loonynino said:
Silly me, lol, forgot the question.

How do i adjust the layshaft pinion meshing?

Thanks
Click to expand...

There is some slight movement with the 4 motor mount screws underneath the chassis plate (and engine!!)

The teeth counts you're giving both add up to 66.
FG normally have 64.
I'm running slightly higher if I remember without any issues.

It MIGHT be that the extra teeth are pushing the engine out of alignment, but I would expect this with a bigger difference to the '64 total' rule.

Start from the motor mounting.
Check that the diff is OK - is it mounted correctly?
Are the bearings OK, not in the stage of collapsing?

Don't worry, sounds a big job, and it is ..... but we all have to do it sometime and it adds to the understanding of the truck.
I'm kidding, it's easy really!!

Al.
 
Loonynino said:
Hi, im new to the website. Just bought a 2nd hand FG marder to try out 1/5 scale as i always been a electric rc man. It came stock with a 23cc engine, looked pretty clean under the shell. Been in storage for a year. It started no problem and ran good.

I then started doing some reading on here and decided to check mine out in more detail. At first noticed spur and pinion were well used so ordered some replacements and upgrades.

Alloy 18t pinion and steel 16t pinion.
Plastic 46t and 48t spurs.

Then noticed on a second run quite a lot of metal noises when running. Upom inspection after bash, thats when i saw that there was a lot of metal shavings under lay shaft and diff. The layshaft pinion is sitting quite far from diff and also only half way out on horizontal contact, if you know what i mean.
I can see that top of the teeth on the 16t pinion had become pointy and narrow, i think thats where the metal shavings are coming from. Diff looks ok.

At the moment gears are:
18t pinion and 46t spur
16t lay shaft pinion and 48t diff.
:(
Click to expand...
yes 18 /46 on the outside is right if thats how you have it and the inside(diff/lay) 16 /48 is right, standard for a marder. the outside gears(spur pinion) should mostly add to 64 like atom explained but you can change the inside lay if you want but its easier to change the outer gears.
either the engine has come loose from 4 screws as explained or the diff brace which attatches to the engine has a loose screw.hopefully you haven't a worn engine mount(if plastic)
i changed my layshaft 3 times as ive had the same problems, gets worse as you use tuned pipes etc but ive found using alloy engine mounts help as they hold the screws better. my next purchase is a alloy diff holders as the screws are becoming loose in the diff mount.my marder is currently out of action due to this matter! but my gears are ok,because as soon as i here that dreadful metal on metal sound,i switch it off
goodluck
 
Last edited:
Thanks guys. Atom u may have your sums wrong, lol. They do add up to 64. I have loosened the engine mount screws and voila! lined it up no problem. The lay shaft pinion has quite a few thin teeth so decided to change it. Guess what? Both grub screws were rounded. Managed to get it off. now has a brand new blackbone layshaft steel pinion 16t. also change outer pinion for an alloy 18t but still running the old spur as new 1s not arrived yet.

Hyper, the engine mounts are plastic but they seem fine for now. Will keep an eye on ebay for the metal 1s. Thanks.:w00t:
 
Loonynino said:
Thanks guys. Atom u may have your sums wrong, lol. They do add up to 64. I have loosened the engine mount screws and voila! lined it up no problem. The lay shaft pinion has quite a few thin teeth so decided to change it. Guess what? Both grub screws were rounded. Managed to get it off. now has a brand new blackbone layshaft steel pinion 16t. also change outer pinion for an alloy 18t but still running the old spur as new 1s not arrived yet.

Hyper, the engine mounts are plastic but they seem fine for now. Will keep an eye on ebay for the metal 1s. Thanks.:w00t:
Click to expand...
i use blackbone mate,they are good gears, and also just get an alloy small engine mount for now,around 15 quid on ebaythe large should outlast the small.the problem with the plastic mounts is that they loopse their thread after tightening alot and come loose.
once you get high up in the gear ratio the total cab be 62.
 
+1 on the small engine mount. Had same thing happen to me . Ied tighten the small engine mount and within 10 min a loude noise from the gear mesh , had to keep re tighten it. Finally bought alloy engine mounts, never a problem since :)
 
Loonynino said:
Thanks guys. Atom u may have your sums wrong, lol. They do add up to 64. I have loosened the engine mount screws and voila! lined it up no problem. The lay shaft pinion has quite a few thin teeth so decided to change it. Guess what? Both grub screws were rounded. Managed to get it off. now has a brand new blackbone layshaft steel pinion 16t. also change outer pinion for an alloy 18t but still running the old spur as new 1s not arrived yet.

Hyper, the engine mounts are plastic but they seem fine for now. Will keep an eye on ebay for the metal 1s. Thanks.:w00t:
Click to expand...

Yeah, you're right on the 64, of course.
Long day at the orifice. ..... .then I missed Q3 as it was just before 01:00 local time and woke up with the TV blasting at 02:00 !!!
Forced myself to see the laptop for the 'live timing' and ... my mate was on pole ... happy days.

Back to case in point.
Engine and diff mounts - usual culprits. Glad you got it sorted.
Later on, as mentioned it can be the diff mount bearing support (if you have plastic diff mounts) that has broken, and/or the bearings are getting stuffed.

Al.
 
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