Our Community is 940,000 Strong. Join Us.


88 grand marquis, 91 transmission


Revelator227
12-22-2010, 08:11 PM
Had a 91 grand marquis that got wrecked. I liked the model so much I got an 88 to replace it, but two weeks into ownership, the OD on the 88 tranny went. Insurance gave me more than I thought I'd get for the car so I bought the 91 back from the insurance and pulled every useful part.

I had the neighborhood grease monkey swap out the transmissions and I have had issues with the 91 tranny ever since.

Preexisting conditions of the 91: Worked just fine, shifted good and strong, no issues. Accident was at 35 mph and transmission mount was damaged.

Preexisting conditions of the 88: Worked fine, but I noticed the shifting sequence took a lot longer, particularly 2nd gear to third gear took longer than I liked and one day the OD just went out, I could still get up to highway speeds but tranny would spin if I pushed it.

When I put the 91 tranny in the 88, the first thing I noticed was that the 91 tranny was shifting just like the 88 was and didn't want to get out of 2 gear cleanly, and after one trip out of the neighborhood it didn't want to shift out of 2nd gear at all. I nursed it to the mechanic I trust to look at it. He wound up replacing the bushings and that made it all work again, it was shifting decently.... however, I noticed that the more I drove it, it began to fall back into the old pattern.... it still shifts, but only after revving higher than normal, and shifting just a tad bit harder just like it did before it failed the first time. I also noticed that it shifts into OD a lot quicker than when it was in the 91. I checked tranny fluid and I see no evidence of burning, though the first time it broke down I could smell a little because I was pushing 2nd gear but hopefully not burning it out, I have not smelled tranny fluid since it has been "fixed". It still works, but because it is a secondary car, it will sit until I find the solution or suck it in and spend money getting a rebuild if that is what it needs.

One thing I noticed when the greasemonkey was replacing the transmission was that the linkage on the 91 transmission was not the same as on the 88 transmission, so he had to open the pan on both and swap out that part from the 88 transmission to the 91.

One thing to note... My brake shoes on the front right are locking up and won't release properly, so I will replace that first.

My guesses are as follows. The greasemonkey did not do the linkage right, there is a vacuum leak, or the transmission was damaged in the accident.... I trusted the greasemonkey because he has replaced transmissions on his own truck and other cars for work and family and his works just fine. Got any suggestions on where I can start looking before I go to the expensive transmission shop? As cheap as these cars are to come by these days I may be better off just getting a properly working Grand Marquis, or maybe a whole different car alltogether, but as I said, this is a secondary car behind two others, so it is my toy... Any good advice appreciated.

way2old
12-26-2010, 03:21 PM
I guess your trouble started with going to a "grease monkey". Not a nice thing to call mechanics or technicians.

dzus
12-27-2010, 01:12 PM
Hey revelator227,
The only monkey on this site is YOU!

PICKUP6772
01-02-2011, 02:47 PM
First, there are NO vacuum lines on the transmission. Second, if the Throttle Valve (TV) cable wasn't adjusted correctly the FIRST time, then it's possible the trans is already cooked. The AOD is VERY sensitive to proper adjustment, and will burn up quickly if not done properly. I had 3rd, and OD burn up as soon as the TV bushing broke. After I put in another tranny, I replaced the nylon bushing with a BRASS one. No more cable problems. Third, did you have the fluid, and filter changed after the trans was installed?? And did he flush out the trans lines and cooler before hooking everything up? And lastly, I hope you take your cars to a real mechanic next time. And if he is a "REAL" mechanic, then you just ticked off a lot of us who are mechanics/technicians with the "GREASE MONKEY" comment.

Scrapper
01-02-2011, 03:32 PM
Hey revelator227,
The only monkey on this site is YOU!

that's right you said the wrong things on this grease monkey i think you need to go to another site.....i'm ASE and theres a bunch of us on here.
it's probably your conuter valves.

scrapper.......

Add your comment to this topic!