PDA

View Full Version : Ideas on what is wrong with my 6sp after rebuild? (long)



MarkChai
04-23-2008, 03:09 PM
Hi and thanks for sponsoring this forum!

I have a 2004.5 A4 1.8t Quattro with a 6-speed manual, and the transmission was rebuilt recently. There are a few things not right with it, and I am sending the car back to the rebuilder under warranty, but I wanted to know your thoughts:

1. When I shift into 4th and 6th, unless I let the RPMs drop to about 1K, I get grinding as I go into the gear, and depending on the situ I can't get the car into that gear at all unless I let the RPMs drop.

2. When shifting into 3rd at higher (above 3500?) RPM, I feel like the shifter sometimes gets "grabbed" out of my hand and into place - almost like there is a little bit of grind there and then the detent or the transmission pops the shifter into the proper position.

3. I usually don't downshift when coming to a stop at a traffic light. I'll coast/brake in gear until I'm in the 1500-1000RPM range, then depress the clutch, let the car out of gear, and release the clutch as I come to a stop in neutral.

Often, it is difficult to get the gearbox into first after that. I usually have to row the shifter toward second then back toward first to get into gear. This also often happens when I start the car into gear for the first time.

I will be describing these conditions to the rebuilder, but I wanted to go into the situation a little more educated if you can help.

Ironically, of all these issues, only the last one existed in any form before the transmission was rebuilt.

Thanks for your insight, and sorry for making the first thread such a hardball! [;)]

IPT Trans
04-24-2008, 04:58 AM
Hi and thanks for sponsoring this forum!

I have a 2004.5 A4 1.8t Quattro with a 6-speed manual, and the transmission was rebuilt recently. There are a few things not right with it, and I am sending the car back to the rebuilder under warranty, but I wanted to know your thoughts:

1. When I shift into 4th and 6th, unless I let the RPMs drop to about 1K, I get grinding as I go into the gear, and depending on the situ I can't get the car into that gear at all unless I let the RPMs drop.

2. When shifting into 3rd at higher (above 3500?) RPM, I feel like the shifter sometimes gets "grabbed" out of my hand and into place - almost like there is a little bit of grind there and then the detent or the transmission pops the shifter into the proper position.

3. I usually don't downshift when coming to a stop at a traffic light. I'll coast/brake in gear until I'm in the 1500-1000RPM range, then depress the clutch, let the car out of gear, and release the clutch as I come to a stop in neutral.

Often, it is difficult to get the gearbox into first after that. I usually have to row the shifter toward second then back toward first to get into gear. This also often happens when I start the car into gear for the first time.

I will be describing these conditions to the rebuilder, but I wanted to go into the situation a little more educated if you can help.

Ironically, of all these issues, only the last one existed in any form before the transmission was rebuilt.

Thanks for your insight, and sorry for making the first thread such a hardball! [;)]

It certainly sounds like there are some problems.

I would hesitate to guess as to what they are based on a written description and not having driven it myself.

I would hope that your rebuilder will be in a better position than I am to figure out what is wrong.

-John, IPT Performance Transmissions (http://www.importperformancetrans.com/)

old guy
05-17-2008, 08:17 AM
I just noticed this new forum and I assume you have already corrected your problem. If not, here is my 2ยข. It sounds to me like your clutch is dragging slightly and not fully disengaging. That would account for your difficulty between gears and the issue with getting it into first from a stop. By bumping 2nd gear before engaging first you have essentially slowed or stopped the input shaft from spinning and the gear will then engage. Before removing the transmission I would first bleed the clutch and see if that helps. If not then you will have to remove the transmission to correct the problem. It could be the clutch disc not sliding freely on the input shaft splines, thus staying in partial contact with the flywheel. Was the clutch replaced at the time of the rebuild or did you reuse what you had? If the clutch and pressure plate was replaced without resurfacing or replacing the flywheel you will often get these symptoms. the flywheel will wear in a bowl shape (.010 to .015" in the center) and consequently the new clutch disc will not have an even contact with the flywheel. So what happens is that the clutch plate actually flexes under clamp. When you press the pedal to release the clutch it will disengage in the center as the clutch plate straightens out but you will still have some contact on the outer edge of the flywheel surface. this causes the clutch drag that results in shifting problems. The 1.8T dual mass flywheel is much more sensitive to this than a typical flat one piece flywheel. Further complicating this issue is the non-adjustable clutch hydraulics. You can get around this problem if it is not too severe by fabricating a slightly longer slave cylinder throw rod.

Good luck!