×
Search (23 Feb 2018)

A trial enhanced search facility has been enabled. Please use the Google Custom Search above.

× A place for general chat about the Jimny. Please make sure you post in the correct section on the site, this way it keeps the site tidy AND ensures you get a more relevant answer.

Suppliers/Dealers or anyone selling with a commercial view in mind CANNOT post here unless responding to a specific request of a member in a "wanted" post.

Suppliers include people "breaking for spares" on a regular basis, when purchasing spares members should ask a supplier what they contribute to the running of the forum particularly if contacted by a Private Message

Suppliers or Members who have contributed to the forum can be identifed by the
logo.[/size][/color][/b]

Jimny crankshaft pulley repair?

  • Orangeherald
  • Topic Author
  • Visitor
  • Visitor
24 Aug 2012 20:44 #46714 by Orangeherald
Jimny crankshaft pulley repair? was created by Orangeherald
I am sure its a familiar fault, the rubber between inner and outer parts of the crankshaft pulley that drives the accessory belts gives up and the pulley falls apart. New one costs about £150 if you can get one. Mine is going and I intend to try fixing it. I reckon with some small plates and a bit of care I can weld the two halves together, and keep the shape and balance right. I will lose the cushioning effect of the rubber, along with its tendency to fall apart. Anyone else tried this? I will of course report results!

Please Log in or Create an account to join the conversation.

  • markyp2000
  • Visitor
  • Visitor
24 Aug 2012 22:01 #46721 by markyp2000
Replied by markyp2000 on topic Jimny crankshaft pulley repair?
its a damper pully for a reason it take some stress of the cambelt/timing chain and easies jults from the pas pump and air con and it is balanced as you say and it will shake its self apart

Please Log in or Create an account to join the conversation.

  • Orangeherald
  • Topic Author
  • Visitor
  • Visitor
24 Aug 2012 23:07 #46728 by Orangeherald
Replied by Orangeherald on topic Jimny crankshaft pulley repair?
I agree they must have done it for a reason, but some makers love those dual mass flywheel type of clutch setups. They cause much pain and expense that I have seen! It is also a common fix to replace those with a solid type. I wonder how important the cushion effect is, and if the self destructing qualities of the Jimny pulley are caused by poor materials or stress from all the shear forces. If the latter then they may do some good. My guess is that the very tight setting of most drive belts simply causes them to self destruct. So, why not a solid pulley and slightly less tight belts? I dont mean loose, just properly adjusted rather than too tight!

Please Log in or Create an account to join the conversation.

  • markyp2000
  • Visitor
  • Visitor
25 Aug 2012 11:54 #46739 by markyp2000
Replied by markyp2000 on topic Jimny crankshaft pulley repair?
again duel mass flywheels take up drive so it is dampened along with the damper pully to take stress off the cam belt and make things run smother and less vibration wour best bet is to take the pully off take it to and engineering company and get one made out off bulet alloy it will be one bit lighter and shouldnt fail and allmost balanced right

Please Log in or Create an account to join the conversation.

More
25 Aug 2012 13:38 #46755 by Obarno
I think the pulley on a Samurai is a solid pulley, albeit the outer ring unbolts. As its essentially an earlier version of the G13B engine I wonder if one of them would fit? Or is it only really the M13 engine that suffers with this problem?

Manual VVT, 2 1/2" lift, ORA castor corrected arms, 2" ORA body lift, Rockwatt transfer box, Uprated front shafts & CVs ERM , ARBs back & front 3.9 diffs, 6 point cage, ORA winch bumper - Superwinch EP9, ORA rear bumper, ORA axle truses, Diff guards ERM , TBR tank guard, Snorkel, Kumho KL71.

Please Log in or Create an account to join the conversation.

More
25 Aug 2012 17:19 #46769 by facade
The pulley is a torsional damper. Its job is to stop the crankshaft breaking.

If you never run at the speed that causes resonance in the crank, you won't need it. Trouble is, we don't know what speed that is :(

en.wikipedia.org/wiki/Torsional_damper

(If you believe the wiki ;) )

If it suddenly breaks, go back to the last thing that you did before it broke and start looking there :)

Please Log in or Create an account to join the conversation.

More
25 Aug 2012 20:40 #46778 by j999pre
Is the engine in yours a g13bb or m13a ?

Gold Jimny the best colour

99 Jimny G16bb w" lift ,extended hoses, caster bushes 16x 7 mods, 225 65 15 muds. radius arm protection, rear disc conversion, snorkel, tow bar and ignis sport recaros.

Please Log in or Create an account to join the conversation.

  • Orangeherald
  • Topic Author
  • Visitor
  • Visitor
25 Aug 2012 22:32 #46786 by Orangeherald
Replied by Orangeherald on topic Jimny crankshaft pulley repair?
The pulley is not like the torsional / harmonic damper on the Wiki page. That is big, heavy, like a flywheel and has no belts on it. The pulley is much smaller and has very thin hard rubber in it. There must be a little damping, but I bet its trivial.The belts also damp it. I though hard, and decided against welding plates over the end. It changes the mass and balance a lot, and alters the place the mass rides. I decided to use four 6mm high tensile pins. These were put in carefully drilled holes, 90 degrees apart, from inside the flange on the inner part of the pulley on the outward facing side, at an angle of about 10 degrees to the rear. They run back to just the bottom of the v grooves on the steering belt part of the pulley, as the belt does not go to the bottom of the groove and it allowed me to get maximum depth, and exact matches. My pins were cut to exact length and snugly fit the holes. I then welded the top of the pins, and ground the weld flush with a diamond burr. I tested balance with a dowel and two knife edges and its as good as original. Now the pulley cannot come apart, without shearing those four pins. My original pulley was 51000 miles old and the rubber was becoming unstuck from the outer about a third of the way round, but was still hard and not degrading. The pulley wobbled when warm at tickover. Now its straight and true. There is no detectable vibration up to 4000 rpm, and I may be imagining it but it seems smoother. I will see how it goes and report any disaster! My engine is an early 2005 M13A with timing chain and no VVT.

Please Log in or Create an account to join the conversation.

  • markyp2000
  • Visitor
  • Visitor
26 Aug 2012 11:38 #46805 by markyp2000
Replied by markyp2000 on topic Jimny crankshaft pulley repair?
did you take any pic of the prosess

Please Log in or Create an account to join the conversation.

  • Orangeherald
  • Topic Author
  • Visitor
  • Visitor
26 Aug 2012 20:39 #46824 by Orangeherald
Replied by Orangeherald on topic Jimny crankshaft pulley repair?
I knew I should have done that, but was so engrossed I forgot. I will try to run up some drawings.

Please Log in or Create an account to join the conversation.

  • Orangeherald
  • Topic Author
  • Visitor
  • Visitor
27 Aug 2012 11:35 - 27 Aug 2012 11:44 #46867 by Orangeherald
Replied by Orangeherald on topic Jimny crankshaft pulley repair?
Two diagrams to show where the pins went. Not to scale but may help to visualise it. The photo of a new pulley shows a spot where the hole was drilled and the weld was done, and the line shows where the pins are.



The drawing shows where the pins are if you cut the pulley in half. Again not to scale, but the pin went from the inner flange to the bottom of the belt grooves, just nicking them to prove hole depth. The belt does not go full depth anyway. What I have done is drill out metal, replace it with metal, but add a little bit through the rubber. Weight increase is tiny, and balance is not disturbed, if the welds are cleaned up properly. It was welded with a stick welder to ensure good burn in.


Attachments:
Last edit: 27 Aug 2012 11:44 by Orangeherald.

Please Log in or Create an account to join the conversation.

More
27 Aug 2012 14:08 #46886 by facade
You could use grubscrews, and threadlock, then no need for welding or grinding out, you can get high tensile grubscrews.

If it suddenly breaks, go back to the last thing that you did before it broke and start looking there :)

Please Log in or Create an account to join the conversation.

Moderators: funkyjimnyooky_123
Time to create page: 0.134 seconds
Powered by Kunena Forum

I hope you enjoy using this forum. Please consider making a donation towards the upkeep of this forum website.