Hello ,

I have jazz 09 i-shift 180k , recently change gearbox clutch with new original oil gearbox , the car is going well on road acceleration and downshift also .But I have another problem after the replacement. When the car is at stop with D inside it make little rattle /vibration with rpm going little down about 100-200rpm . If I put it at N the problem stop. Only at D is doing this and after the clutch change . Also I have new spark plugs and throttle clean and adapt.

 

I would start by using a OBD scanner and see if any codes are coming up. That might flag some basic issues and give you a hint at what the car sees is not working correctly.
Outside of that, have you messed with the idle at all. Possible the idle is too low. But I would also think that the OBD would flag most of the idling issues.

 

No errors on obd scan , nothing . When I put N the car is working perfectly no rpm is going up / down .
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The car has no errors nothing

 

Vacuum leak?

 

Dude.. I have this same issue with our Tacoma (since purchase). I tried doing an idle re-learn, cleaning the TB (gently!) and the injectors, replaced spark plugs, air filter, did multiple thorough checks for vac leaks and verified vac line routing, replaced engine and transmission mounts. I even replaced the converters to get rid of the only pending code.

The only things I've got left are maybe timing or like.. I'm gonna freshen up the cylinder head if I ever get time. I know it can't be perfect because the truck was in a front end collision before we got it, so it likely overheated.. and I know it sat because as an 09 it only had 45k miles on it when we got it two years ago. I guess the throttle body could be screwed up in some way, but would expect a code.

This fault has been really hard to chase down for me, and I haven't been able to find anything conclusive even when doing a general search for all vehicles. The best lead I got was exhaust harmonics. It fit with the code but not the idle speed, and as mentioned I addressed it.

If you come up with anything, please update 😂 you have my undivided attention

EDIT: actually after re-reading, your problem is likely caused by the tranny if that's all that changed.. maybe my issue is there too. Identical fault, except mine came with the (used) truck.

 

So man , my thought is that something in the gearbox make the car to vibrate . Before change clutch the car had NO problem at all !!!!
the workshop told me that is normal to do this after replacement , but I dont believe that

 

I'm not well-versed or versed at all with transmissions. I did the clutch and flywheel on my fit, and fluid changes.
When doing so I tried to get the new clutch balanced with the flywheel, but the local machinist didn't have a small enough arbor to spin the assembly on, or so he said. 😂So I ran it without a balance.. and it's been pretty fine so far as I could tell.

Balancing these assemblies really isn't magic, you just spin them on a proper diameter rod, the heavy side (if there is one) will stop at the bottom and you can stick a washer on the opposite high side with tape or a small magnet, whatever. repeat until it doesn't stop in the same place twice, then weld on the washers. alternatively I think manufacturers drill partial depth holes in the heavy side.

I suppose it's possible that the torque converter on an automatic could be out of balance with the flex plate and that could generate vibration/be a problem created by replacement of those components.. but that wouldn't explain the low idle.

Similar to your experience the two mechanics that checked out our truck pre-purchase said: "it's a truck, it vibrates."

I'll try and get the thing over to a transmission shop instead to see if they can give a diag. You may be interested in doing the same and bringing that report back to the original shop that rendered the repair.

 

My opinion to this challenge is that something is not perfect align in the procedure while they install it . I will take it back to workshop and fix it !

 

I wish you luck. I'd love to hear a legitimate diagnosis for this problem