One for the cam gear experts

Started by Myfirstbuggy, July 18, 2022, 05:38:06 PM

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Myfirstbuggy

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Beach Buggy
Posts: 145
None ye
Location: ne5 5as
Starting to build my 1600 TP , crank and rods all fine , but I'm not happy with the rotation of the camshaft , it just doesn't feel a smooth or fluid movement when the crank is turned ,all the main bearings on the crank are fully seated , the cam isn't jumping out of the bearing carriers , just doesn't feel right , could it be badly matched cam gears , anyone use straight cut cam gears , is that the way forward ?     
myfirsybuggy

Paul1953

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Buggy Prince
Posts: 3,489
MANX SWB
Location: Newton Aycliffe, Co Durham
Trust your instincts... If it "doesn`t feel right" it probably isn`t. Farmer Rob will come along with advice....

snoopy

MBC Moderator
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Buggy Expert
Posts: 11,201
Kango ss/ Jas lwb
Location: evesham. 07757010432
straight cut gears will be noisy, have you torqued up the case with the cam and crank fitted to check the rotation or just done it open on the bench.

Myfirstbuggy

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Beach Buggy
Posts: 145
None ye
Location: ne5 5as
just done it open on the bench
myfirsybuggy

snoopy

MBC Moderator
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Buggy Expert
Posts: 11,201
Kango ss/ Jas lwb
Location: evesham. 07757010432
Some engineers blue is your friend it will show you how all the teeth mesh after 2 full crank rotations best done with the case together and the big nuts torqued up.

farmer rob

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Buggy Meister
Posts: 1,789
SWB Rat
Location: northants
Have you fitted a new camshaft and bearings? And have you fitted one or two thrust bearings? I fit the camshaft first in the case half that has the thrust bearing or both if your fitting two, and then check for 3-4 thou end float between thrust bearing and cam thrust edge. If you haven't got this, sometimes a clout with a drift on either end of the camshaft while fitted; will square the thrust sides up so you have clearance. If not, just rub the thrust surfaces on a fine oil stone till you get the clearance. When you are happy with that, fit the crankshaft in the case half, when you are happy the bearings are sitting correctly on all the dowels, Fit the camshaft. Genuine VW camshaft gears came in different diameters. So the cam gear should be able to rock in the crank gear! If its too tight, it will walk out as they say, when you turn the crankshaft round one way. As you say it doesn't feel right, it might be the crank gear got damaged taking it off or re-fitting it. Just turn the crank round one tooth at a time and see if the cam gear will rock each time. As Snoopy say's, some engineers Blue will highlight a damaged tooth which you could then rub down with an oil stone.

Hope this helps Rob

IDA

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Buggy Baron
Posts: 513
Mk2 Rat and LDV
Location: CHICHESTER
straight cut cam gears are not needed and after so long they get on your tit.. And is why straight cut gearbox's 4-5 etc are not straight cut ..
Do not be offended by my spelling mistakes! Why asking tech? questions" As so far I have not asked Any,, Everyone fort it was in possible apart from the One who invented it..

Myfirstbuggy

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Beach Buggy
Posts: 145
None ye
Location: ne5 5as
Quote from: farmer rob on July 19, 2022, 02:19:06 PM
Have you fitted a new camshaft and bearings? And have you fitted one or two thrust bearings? I fit the camshaft first in the case half that has the thrust bearing or both if your fitting two, and then check for 3-4 thou end float between thrust bearing and cam thrust edge. If you haven't got this, sometimes a clout with a drift on either end of the camshaft while fitted; will square the thrust sides up so you have clearance. If not, just rub the thrust surfaces on a fine oil stone till you get the clearance. When you are happy with that, fit the crankshaft in the case half, when you are happy the bearings are sitting correctly on all the dowels, Fit the camshaft. Genuine VW camshaft gears came in different diameters. So the cam gear should be able to rock in the crank gear! If its too tight, it will walk out as they say, when you turn the crankshaft round one way. As you say it doesn't feel right, it might be the crank gear got damaged taking it off or re-fitting it. Just turn the crank round one tooth at a time and see if the cam gear will rock each time. As Snoopy say's, some engineers Blue will highlight a damaged tooth which you could then rub down with an oil stone.

Hope this helps Rob
[/quote Thanks , I'll try that
myfirsybuggy

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