Date: 20 Sep 1997 21:48:57 -0400 From: kenbellnopsamx.com (Ken Bell) Subject: Re: Lunging '88 900s!!!
In article <19970916235200.TAA08763nopsamer01.news.aol.com>, Maboul <maboulnopsamcom> wrote: > >I have an 88 900s Saab, Automatic. It shifts really hard, and sort of >lunges you forward when shifting gears. I can sometimes get it to lessen >the lunging effect if I let up on the pedal, but it's really annoying and >doesn't always work. What can be adjusted on the transmission to lessen >this effect, other than getting a new transmission. Please e-mail any >responses as I'm not able to check message boards for some reason! Thanks. First, are you familiar with the characteristics of this A/T when it is new? The ZF tranny, for example (the only one I'm familiar with, on the 9000) is know for its "firm" shifts, and they can feel positively harsh to someone who is used to a GM shift. Sometimes people report A/T problems magically disappear when they change the A/T fluid and filter/screen. Sometimes, however, I have read that a box that has never had fluid/filter service in many miles will suddenly self-destruct when the fluid is changed, so use your judgment here (and consider the service history of your car). I don't know about the 88 900S A/T, I think it's by Borg-Warner. So what I say may not apply to your car, because it's written for the ZF "4 HP 18" used in the 9000, but just in case ... The "Fault Diagnosis" section of the Saab 9000 service manual, "4:2 Automatic transmission" offers the following probable fault and remedial action pairs for the harsh shifting: Symptom: Downshift too harsh 1. Fault: accumulator funtion defective Remedy: fit a new valve body 2. Fault: modulation pressure too high Remedy: fit a new valve body 3. Fault: clutch plates damaged Remedy: fit a new transmission unit (Ouch!) Fitting a new valve body is also suggested for jerky engagement when selector is moved from "N" to "R" or "D", and for missing gears, e.g., 1-3 or 1-4 upshift. I have read elsewhere that there are a couple of springs in the valve body that can be easily and cheaply replaced (DIY) to cure jerky N->D or N->R engagement. >Evan Jacobs >Maboulnopsamcom (just b/c my ISP doesn't carry alt.autos.saab!!!!) OK, I emailed you a copy. So why don't you ask them to add a.a.s. ... doesn't AOL honor customer requests? -- Ken Bell :: kenbellnopsamx.com :: (212) 475-4976 (voice) ======== :: syklbnopsam.nasa.gov :: (212) 678-5516 (voice), 678-5552 (fax)