jw97C2S

I have the typical power seat (back/forth) cable failure that I've heard occurs on 993's (right side cable snapped). Does anyone have the part number for the cable so that I can order a new one. The local dealer is of no help. Thanks for any help!

Jim

Robin 993DX

I have the part number listed under the power seat drive shaft DIY in my web site.

P-car.com

jw97C2S

Thanks Robin! You came through yet again. Wish I had seen your DIY article before spending a half an hour figuring it out myself. Thanks again.

Jim

Robin 993DX

Jim,

I might be more at fault at this than you. I just finanly documented this DIY this past weekend when I fixed the shaft in my own car. So this is a fairly new DIY that was added, so I don't think you would have found it anyways.

Thanks

Robin

JPhillips-998

Robin,
I have the problem with my passenger seat but it is only on an intermittent basis. Any ideas?

Robin 993DX

There could be several possibilities, it cold be a bad switch or that there might be something stuck in the seat tracks.

I would recommend you follow the DIY listed in my web site to take off the flexible seat drive cable and check the ends of it to see if it is torn. If it is in good shape I would swap the seat switch to the driver's side and see if the problem would follow it to the driver's side. The last resort is to shake the seat left and right to loosen any articles that is stuck in the seat rails.

If all else fails, unbolt the seat and get a better look under the seat rails.

Anir

My passenger seat has developed a slightly different problem. When trying to lower the front lip of the seat bottom, the inner edge of the seat falls further than the outside edge. In other words, the front lip of the seat (under the knees) tilts toward the center console. The rear seat bottom height adjustment appears to be intact on both the inside and outside edges.

The only way to make the seat level is to bring the front seat lip up to its highest level. The entire seat moves back and forth without difficulty.

Has anyone else experienced this problem? I suspect an individual motor is bad. It would be nice to order the right motor, cable, etc. before removing the seat.

Thanks.

Robin 993DX

Anir,

The front vertical movement is controlled by one single motor. The motor is certainly good in your situation, since the seat moves up and down. The vertical motor also drive two flexible shafts just like the forward and backward drive motor, but in this case one shaft is longer than the other, the shaft on the right side is longer, (928 521 672 03), the shaft on the left side is shorter (928 521 671 03), on each end of the flexible shaft there are the vertical lifting gear which lifts the seat up and down, 928 521 721 03 (left), 928 521 722 03(right).

Two possibilities I can see here, (1). The drive shaft cable is torn at the ends, so as the motor moves one side is slipping and causing it not to move equally. (2). The vertical lift gear is bad, so one side lifts up faster than the other side.

I would check the flexible cable shaft first and then move on to the vertical lifting gears.

Anir

Robin,

Thank you so much for the response and for the very helpful diagram by e-mail. I have modified your very nice color diagram to a monochromatic pic so that it could be posted here for others' benefit.

Looks like the seat is coming off tomorrow.

Anir

Robin,

Thanks again for the great diagram. It turns out that the right front vertical gear is not functioning at all. The gear's pin is stuck at its highest position. There appears to be activity (vibration) in the right shaft (928-521-672-03), but I can't be sure. I'll probably order both the right shaft and gear, just to be safe.

I've got a couple of questions. Are the part numbers in your helpful drawing appropriate for the 993TT (I noticed the prefix was "928")?

And second, the gear appears to be bolted to the frame from underneath, so I suspect I should remove the seat off the track to access the bolts. Is this correct? How is the seat removed from its track?

I really appreciate your help. I own the two Turbo service manuals, and I think it's time to order the eight 993 manuals as well.

I'll make you a deal. If you help me through this, I'll document the repair with photos so that we can add it to your DIY section.

Robin 993DX

Anir,

Exactly what kind of seats do you have in your 993tt? Sports or normal? If it is the normal 993 seat then the part number I gave you is the correct part number. Many parts from the 993 power seat are from 928s.

I would assume that you should at least remove the seats out of the car to perform this surgery, as far as removing the seat from the track, I have never done this before so I don't have much to tell you there.

Anir

Robin,

I have the optional sports seats. Do you think the numbers still apply? If you're not sure, I'll call Phil Anderson at Suncoast.

Do you know how to take the seat off in general? Once it is off, it seems like I could remove the frame off the track if needed to access the bolts.

Thanks.

Robin 993DX

Anir,

It looks like the parts number are the same.

Flexible shaft 928 521 671 03, 928 521 672 03, verticle gear (left) 928 521 721 03, (right) 928 521 722 03

For instructions on how to remove the seat please check out the DIY section of my web site under (how to install a EPROM chip).

Please do not use a cheap allen key to remove the seat bolts, get yourself some quality allen driver bits from either Sears or a Snap tools tool truck. If you happen to strip the allen seat bolts please check out the "Technical section" of my web site under how to remove stripped allen bolt written by pops. (Ray Calvo)

Good luck

Robin

P.S. You could always ship the seats down to me to fix... LOL

P-car.com

Anir

Thanks for all the help, Robin!

Anir

Robin,

Thanks to you, I was able to repair my passenger seat today. I replaced the right vertical gear 928-521-672-03 ($103.65 from Suncoast), and it now works perfectly (all four corners rise and fall together).

It's impossible to get to the 19 mm nut fitting over the shaft of the vertical gear without partially disassembling the upholstery and cushion. Basically, you have to access this nut from above (through the seat).

As you might recall, you suggested that the shaft connecting the motor to the gear might be the culprit. In my case, it was fine, but I replaced it anyway since it was cheap (# 928 521 672 03, $7.88). Honestly, these shafts are solid braided metal, and don't seem very prone to failure.

If anyone ever experiences a problem where only one corner of your power seat won't rise or fall, it's almost certainly a seized or broken vertical gear.

Thanks again for all your help, Robin!