OzVMX Forum

Clubroom => Tech Talk => Topic started by: Vince H on August 19, 2014, 05:59:06 pm

Title: 77 DT175 clutch trouble
Post by: Vince H on August 19, 2014, 05:59:06 pm
Hope someone can help me. Can't get my clutch to engage on my DT. Had to pull side cover off to fix so took motor out of frame to give a clean up . I didn't disassemble anything other then what had to be to get clutch side cover off and motor out . Am only learning about how bikes go together so don't know a lot yet. Any help would be appreciated even on how the cable is setup
Title: Re: 77 DT175 clutch trouble
Post by: matcho mick on August 19, 2014, 08:21:46 pm
pass ;D, :P
ps apart from did a ballbearing fall out of clutch "worm" drive in sprocket cover,common "doh" problem??
Title: Re: 77 DT175 clutch trouble
Post by: crossedup2 on August 19, 2014, 09:58:36 pm
This is what Mick is talking about; Part number 25 (yes I know its the IT175 but they are all very similar)

(http://i1087.photobucket.com/albums/j476/crossedup2/Clutch175_zps4c76f1d8.jpg) (http://s1087.photobucket.com/user/crossedup2/media/Clutch175_zps4c76f1d8.jpg.html)

The single ball allows the shafts not to weld together and to allow the clutch side to spin but not the end against the actuator.

Single biggest stuff up on reassembly you can make with these motors. There is a method of adjusting all the parts of the clutch. Better going back to the manual. But first check that the ball bearing is still in the middle of the input shaft of the transmission.

Mick, "D" models didn't have the worm drive, just the lever cam.

Peter B
Title: Re: 77 DT175 clutch trouble
Post by: Vince H on August 19, 2014, 10:22:50 pm
Cheers fellas will check tomorrow anyone know where I can get the rods and bearings from if needed
Title: Re: 77 DT175 clutch trouble
Post by: sleepy on August 19, 2014, 10:26:48 pm
What do you mean by engage?
When a clutch engages the motor drives the back wheel.
When it dis-engages the motor turns but not the wheel.
Title: Re: 77 DT175 clutch trouble
Post by: Tex on August 19, 2014, 10:33:00 pm
I had a similar problem with my 1977 DT125. I hate to tell you this but all I did was cable tie the lever against the handgrip so that there was constant pressure being exerted, and left it for a week or so. It freed itself up and has worked perfectly ever since!

If you've only taken the cover off and not messed with anything else you shouldn't have lost any parts.

My 125 would be pretty similar to your 175, so if you want a photo of how the clutch cable is routed let me know. Not saying that mine is necessarily correct but it works.

Tex
Title: Re: 77 DT175 clutch trouble
Post by: Vince H on August 19, 2014, 10:55:10 pm
Yeah tex thanks a pic would be good. when I pull lever it pulls accuator but won't let motor turn freely or spring back
Title: Re: 77 DT175 clutch trouble
Post by: vandy010 on August 20, 2014, 07:51:11 am
Yeah tex thanks a pic would be good. when I pull lever it pulls accuator but won't let motor turn freely or spring back
Not letting the motor turn freely sounds like the usual old bike with a stuck clutch scenario...
A clean up of parts, clutch plates etc and some fresh oil should make it better...
but the "not springing back" part could be a shitty old clogged up cable...
is the clutch cable stiff to use?
Either a new cable or soak and clean the old one etc
Title: Re: 77 DT175 clutch trouble
Post by: Vince H on August 20, 2014, 04:25:04 pm
Well just realized I made a mistake it s a 1976 model DT not 77. Does the 76 still need the little ball bearing that goes between the push rods if so u guys were right I've lost that. Does anybody one know the size of the ball bearing or where to get one
Title: Re: 77 DT175 clutch trouble
Post by: Momus on August 20, 2014, 05:50:50 pm
Ball is slightly under the diameter of the pushrod; <5 mm if I recollect.

A pushbike shop (or dead pushy crank bearing) or a CBC/ bearing shop.
Title: Re: 77 DT175 clutch trouble
Post by: Vince H on August 20, 2014, 06:40:13 pm
Thanks momus
Title: Re: 77 DT175 clutch trouble
Post by: Tex on August 20, 2014, 09:22:11 pm
Quote
when I pull lever it pulls accuator but won't let motor turn freely or spring back

Ah, mine was springing back ok. Good luck with the part. I'll send a pic of the cable routing when I get a chance. There's probably a diagram in owners manual if you have one.

Tex
Title: Re: 77 DT175 clutch trouble
Post by: crossedup2 on August 20, 2014, 10:46:07 pm
Parts web page says its 3/16"

93503-16010-00 BALL 3 --- BALL 3/16,

Weirdly enough its the same part number as the smaller balls as the (original) steering head bearings.
There are two sizes, they being 3/16 and 1/4 inch.

Peter B
Title: Re: 77 DT175 clutch trouble
Post by: OverTheHill on August 20, 2014, 11:19:13 pm
without going through all answers [sleep time] think you said you 'hadn't' had the clutch apart but had--had the cover off only. Working on the theory that i misunderstood i'll imagine you had the clutch pressure plate off [end plate] & put it on wrong--think you get 3 shots of getting it right but has 5 springs, so if it's wrong it sits against end of splines instead of 'on' them, consequently it wont drive [engage] as plates not compressed. Sorry if i got the wrong end of the stick--just a hunch. If you realy didn't touch anything except have cover off & back on then--i give up, for now anyway. Good luck.
Title: Re: 77 DT175 clutch trouble
Post by: Vince H on August 21, 2014, 04:01:35 pm
All fixed thanks for the help fellas
Title: Re: 77 DT175 clutch trouble
Post by: crossedup2 on August 21, 2014, 05:54:45 pm
So what was it in the end Vince?

You need to tell!

Peter B
Title: Re: 77 DT175 clutch trouble
Post by: Vince H on August 21, 2014, 07:37:49 pm
The little bloody ball bearing that goes between the push rods must have fallen out when I was checking the clutch out lol  ::)
Title: Re: 77 DT175 clutch trouble
Post by: GMC on August 21, 2014, 07:53:00 pm
That crazy little ball bearing didn't fall into the gearbox did it?
Title: Re: 77 DT175 clutch trouble
Post by: OverTheHill on August 21, 2014, 07:57:13 pm
Oh god--ok, you found it didn't you?, sorry shouldn't ask thing like that. On the later DT175's we had special v shaped rubber ring supplied to stop the clutch rattle at idle. rattle from the drum moving on the built in cush rubber i suppose and/or making it chatter on the clutch drum teeth to the crank gear [something like that]. The heavy rubber ring got stretched over the drum & fitted tightly at the top between the drum & the gear effectively damping the rattle out, worked too.
Title: Re: 77 DT175 clutch trouble
Post by: OverTheHill on August 21, 2014, 08:00:26 pm
just wrote that GMC & was too chicken to tell the story of the outcome of that. Worst part is when you pull the whole motor right apart & wifey comes along & says--is this what you're looking for over here, Grrr.
Title: Re: 77 DT175 clutch trouble
Post by: Vince H on August 21, 2014, 09:31:06 pm
No must have.fell out on work bench then shed floor yeah know what ur saying was working on my xr the other day and couldn't find part searched everywhere gave up looking then mates misses comes in saying is this what u were looking for lol  >:( ::)