1994 850 Turbo Loud clunk when shifted into reverse.

motovolvo · Post by **motovolvo** » 08 Nov 2014, 21:41

Hello,

Today I put front brakes on my 850 and I also tore open the dash to replace the broken gear in the odometer as well as replace the light bulbs. After I finished the brakes, I said "hello" to my turbo that leaks like a sieve and wiped up some of the oil in that area. Then last, I changed the oil and filter.

To my dismay and horror, my Volvo now clunks like all hell when I put it into reverse. I cannot figure out why either. It had never done this before and all the other gears currently shift fine. I checked the Trans. fluid and it is at full. The cluck is so intense that when I put the car in reverse I can see the lights dim, telling me it is putting a huge load on the engine.

It really seems like this is something I caused when I was working on it today. I did have the car jacked up for several hours but I don't see what problem that could cause. I am also quite sure I jacked the car up in the correct locations as well. I am very sad and worried about my precious 850 wagon. I hope someone can help. Thanks.

Post by **rspi** » 09 Nov 2014, 06:51

Have you checked the mounts? Have you ever replaced the trans fluid?

Post by **rspi** » 09 Nov 2014, 06:53

Transmission fluid change:

Post by **Volvofan94** » 09 Nov 2014, 08:16

The transmission in my 94 Turbo clunks into reverse as well. It doesn't sound as bad as the clunk you describe. I did a trans flush and fill about 5k miles ago and it's gotten better, though it happens if I shift from Drive to Reverse. On mine the clunk happens when the engine is up to temperature. Does the clunk happen when the engine is at temperature or cold?

motovolvo · Post by **motovolvo** » 09 Nov 2014, 12:44

The trans fluid is far from burnt, it is still quite red. Although I have never changed the fluid, the previous owner must have because I have put less than 20,000 on the wagon since I owned it...it has 290,000 on the vehicle. If the fluid was the issue wouldn't I have problems shifting into all gears? I will check the mount and report back. I don't think it would hurt to change the fluid, so maybe I will try it.

The cluck is more likely to occur when the engine is at temperature, I never thought about that until it was mentioned.

Could I have bumped a sensor or cable, causing all this to happen?

VolvoFan94, how long has your trans. been clunking?

Post by **rspi** » 09 Nov 2014, 15:55

motovolvo wrote:The trans fluid is far from burnt, it is still quite red.

It doesn't have to be burnt, just dirty and warn out. People tell me "it's good a red" all the time, until I drain it in a pan, and they see no redness in a plastic bottle. The thin film on the dip stick is not a good sight check for the color. I have changed the fluid in every P80 Volvo transmission I have had, will no ill effects.

Post by **Volvofan94** » 10 Nov 2014, 19:27

VolvoFan94, how long has your trans. been clunking?

The trans on my 94 has been clunking when shifting to reverse since I've owned it. I've owned mine going on a year and a half now. It was much worse when I first bought the car because the transmission fluid needed to be changed, but after I changed it, the clunk was better. Also mine, at the same time, had a high idle problem when the engine was up to temperature and the car was in park. This would make the clunk in reverse worse. I fixed the surging idle (~1500 rpm - hot engine) and it helped reduce the clunk, but it's still there though the RPMs are normal.

How high are the RPMs when your car is in park?

-volvofan94

Post by **scot850** » 10 Nov 2014, 20:18

Don't think it is anything to do with the transmission. Check all your engine mounts carefully. Pay particular attention to the one under the crank pulley, and the top mount. Also check the lower torque mount under the engine/trans

Neil.

motovolvo · Post by **motovolvo** » 15 Nov 2014, 18:53

Update: I changed the trans. fluid which yielded about 3.75 quarts of the 7.4 its holds. I drove about twenty miles and I still have the clunk, the clunk only manifests itself after the vehicle is at temperature. I looked at the mounts, particularly the mount for the trans. and it looked good. No cracks or rips. The rest of the trans. appears to shift and function just fine, except reverse. I found a long unused road and drove it in reverse for a good 300 ft. and it was slipping all the way. Even after the fluid change.

I know that the turbo leaks oil, but the oil leak from the turbo has gotten terribly worse. At the same time I now smell oil in the cabin upon even the smallest acceleration. Furthermore, my turbo gauge on the dash use to read at exactly the half-way mark and in fact when I turn the car off it will return to the half way mark. Now it reads at the low end of the turbo range when at idle and while driving, it appears to be producing hardly any turbo boost at all.

Since I can see some light smoke venting from the oil dipstick, I know I need to do the PVC service. I am still mystified by the trans., it legitimately seems to be slipping in reverse. My turbo most likely needs to be replaced, should I put in a junk yard turbo or spend the cash on a reman.? Has anyone here removed and replaced a trans from a 94 Volvo? Are their any write ups? Has anyone here ever removed and replaced a turbo? I am very open to suggestions here. Thanks.

Post by **xHeart** » 16 Nov 2014, 07:51

The clunk in my situation was the gradual tearing of a crack in coil/spring at passenger side. I did not know the cause of clunk each morning when reversing out from our garage.

It became louder during the course of a year.

The passenger side spring finally broke while putting the front wheels on the pair of ramp for an oil change.
I have replace both front springs with OE. The clunk has been absent since.

I say, start with replacing each mount if you haven't already.