No Forward

[merkur]

Well I have searched and searched, and cannot find the answere. I was driving along, and it acted like it popped out of gear. just like that i had no forward gears. Drove it home in reverse. It is a 87 a4ld. I have found two or three posts with the same symtoms, but have never seen an answere. It never had slow ingagement, or symptoms of any kind up until the moment it went pop, and then nothing. Oh yea and it had the usual rebuild 10,000 miles back obviously by someone incompetent. Also, where can I get a heavy duty high stall converter? Thanks alot!
Danny

 

[BrooklynBay]

Welcome to this forum! Did you check the fluid level?

 

[merkur]

In my searching I have seen your reply about the fluid level many times. I would not dream of posting about a problem without checking the fluid level first, all because of you. The transmission is in a Thunderbird Turbo Coupe. I was working on upgrades to the turbo, and had power braked it a couple times in the drive way for about 4-5 seconds to check boost response. I then took it for a drive to adjust the boost controller. I wasn't beating on it, I was in manual 2nd smoothly pressing the throttle to the floor for about 3-4 seconds until full boost was realized, and let off and shift to 3rd coasting. I did that 3 times( That was all it took to adjust the boost)and was just driving normally when I pressed the throttle and there was nothing. Fluid in good condition, temps normal. Any Ideas?

 

[BrooklynBay]

The modulator on the turbo equipped A4LD is some how different than on the regular A4LD, and is a lot more expensive. Just out of curiosity, does the modulator have one, or two vacuum lines? Check those lines for ATF. Most have a single diaphragm, but I think there are some types with dual diaphragms. Reverse gear has higher pressure than the drive gear, so a 0-300 PSI gauge would come in handy about now.

 

[BrooklynBay]

I saw your other thread in the new members forum. So this car is your friend's car?

 

[Glacier991]

While there could be other things, there is a strong liklihood your front sprag (one way clutch) is damaged from what you have desscribed.

 

[merkur]

Yes it is my friends car. I had thought the front sprag might be the problem. The modulator is a single vac line, and I had replaced it(the modulator) a couple years ago. The car doesn't get driven alot. It dynoed a little over 200 ftlbs of torque and 190 hp to the wheels, so it is not over powered. I was wondering if a valve body gasket could have popped and caused something like that. Just wishing I guess. In the last week we have pulled it out, but not torn it down. We picked up a 94 4.0, and 97 5 speed 4.0 core to start a frankentrans project if it is not something we can fix without a complete tear down and rebuild. Any other ideas? Oh, and thanks alot for the replies.
Danny

 

[BrooklynBay]

Dropping the pan would be a good way to start. Check for broken parts in the pan.

 

[Glacier991]

If the front one way clutch (OD Sprag) has failed as I suspect.... the OD planetary piece that it grabs has broken loose. If so it stays in place as it is captured by the sprad assembly inside a ring hear hub. Odds are you will not find anything in the pan, but always a good idea to check.

 

[merkur]

Thanks for the replys. I think I am going to use the 4r 4.0 case and internals to rebuild, and put on a 2.3 bell housing. After we get the T bird back on the road I will look at the other two that are left. A A4ld and 5r55e, using the A4 in my Merkur, and the 5r in the project switching a 4.0 and 5r into my wifes Isuzu pickup. So I guess I need to start looking for a donor for the transfer case, engine, and wire harness. Look's like your stuck with me for a while! Later
Danny

 

[blkpanther]

New Member - Would like price quotes on a used A4LD.

Thank You (in advance),

Randal