86 760 turbo shifts very hard

thomastedder · Post by **thomastedder** » 01 Apr 2008, 17:44

Hello. Sorry to start my first post with a technical question, but I just bought a sweet old volvo and have a minor problem. It shifts REALLY hard into second gear. Third is not as bad, but still too hard. In addition, it never shifts into 4th. It is at 3000 rpm at 50 mph. I know that can't be right. I was wondering if the hard shifts and lack of 4th gear engagement are related? Is there an adjustment for this that anyone knows of? I looked at the throttle and noticed a cable that goes down toward the transmission. Could this be similar to a throttle kick down lever? The previous owner (little old lady) said she took it to a transmission mechanic and he told her that he serviced the transmission, but there was nothing wrong with it and Volvos just shift hard when they get old. Now, I'm no transmission mechanic, but I think she got ripped off by a lazy, stupid, or dishonest mechanic. Do they shift hard? Is there a 4th gear I'm not getting into? Can the tranny be adjusted by that cable or by some other means?

Post by **billofdurham** » 02 Apr 2008, 11:54

Welcome to Matthew's Volvo Site.

4th gear first. This is automatically engaged unless the button on the left side of the shift lever is pushed in. With the button in it will not change into 4th and the yellow arrow will be lit on the dash. Try pushing the button again and see what happens.

Hard shifting into gears does not happen to every Volvo as it grows old. Check the fluid level after a run of about 30 minutes to get the fluid up to working temperature. Stand vehicle on a level surface, engage parking brake and select 'P'. Start the engine and let it idle for a couple of minutes. Shift the lever through all the gears pausing for 4 - 5 seconds in each gear. Return to 'P', wait 2 minutes and, with the engine still idling, withdraw the transmission dipstick. Wipe it off with a lint free cloth and reinsert it. Withdraw it again and check the reading. Level must be between the Max and Min marks. If it is not then add or remove fluid as necessary.

Whilst doing the check look at the colour of the fluid and smell it to determine if it is 'burnt'. The fluid should be a good red colour.

The cable going from the throttle to the gearbox is the kickdown cable which can be adjusted but I don't think with the symptoms you describe that it is the problem.

Bill.

thomastedder · Post by **thomastedder** » 02 Apr 2008, 13:14

I forgot to mention that the button is inoperable. It does not do anything. No lights or gear changes.

I checked the tranny fluid before I bought it. It is new fluid and it's at the right level, but I just did about a 20 minute warm up (test drive).

Post by **billofdurham** » 02 Apr 2008, 15:51

I forgot to mention that the button is inoperable

That is probably why you have no 4th gear. The switch can be pried out quite easily. Check the connections and see if you can get the switch to work outside the shift lever. If not I would suggest a new switch.

The majority of auto box problems can be traced back to fluid, kickdown cable or selector mechanism adjustment.

The fluid appears to be new and the level is good but do you know which fluid was put in by the "transmission mechanic"?

To check the kick down cable pull it out by hand approx 10 - 15 cms (.39 - .59 inches) and release it. A distinct click should be heard from the transmission indicating that the cable is moving freely and the throttle cam returns to its initial position. Now depress the accelerator pedal completely. The transmission cable should travel 50 - 53mm (1.98 - 2.07 inches) from idle position to full throttle position.

To check the selector adjustment press on the gear selector and check that clearance from 'D' to stop is approximately the same as for '2' to stop. If it is not the control rod needs adjustment.

Adjustment is made by turning the clevis in or out on the control rod. The maximum visible thread length is 28mm (1.1 inches). Increasing the rod length reduces position 'D' clearance and vice versa. Shift to position '1' and then 'P' to recheck.

Other than these checks there is little that can be done by DIY.

Bill.

thomastedder · Post by **thomastedder** » 02 Apr 2008, 16:46

Good stuff Bill. Thank you very much. I didn't think the switch would be a problem, because the manual says that it disengages 4th gear and lights a light on the dash. I figured that would mean I couldn't disengage 4th gear since the switch doesn't do anything. I'll try to clean that switch. If that don't do it I'll check the other two adjustments you mentioned.

Also, good point about the fluid. What kind does it take? Dex?

Post by **billofdurham** » 03 Apr 2008, 11:46

The fluid should be changed every 20,000 miles according to the Volvo maintenance sheet so it probably won't look much different from new stuff if it has been changed regularly.

It does take Dexron 11D.

Bill.

lucast · Post by **lucast** » 07 Apr 2008, 15:32

Hi Thomas

The 4th gear problem - that's your overdrive (OD) relay not working for some reason. Mine was intermittent.

Check out the 700/900 series FAQ at brickboard.com for possible solutions.

I discovered that for me, the issue was cracked soldering joints in the OD relay itself, and it was an easy fix with a soldering iron. But the problem could be with other parts of the OD circuit as well - see the FAQ.

Most of these problems are documented and correctable.

Regards
Lucast

lucast · Post by **lucast** » 07 Apr 2008, 15:35

thomastedder wrote:Good stuff Bill. Thank you very much. I didn't think the switch would be a problem, because the manual says that it disengages 4th gear and lights a light on the dash. I figured that would mean I couldn't disengage 4th gear since the switch doesn't do anything. I'll try to clean that switch. If that don't do it I'll check the other two adjustments you mentioned.

Also, good point about the fluid. What kind does it take? Dex?

Dexron III spec or better. Some feel that a synthetic ATF will help alleviate the hard shifts

thomastedder · Post by **thomastedder** » 07 Apr 2008, 15:40

Thank you. I'll go over there and check that. I've been looking for a book, but can't seem to find one.

lucast · Post by **lucast** » 08 Apr 2008, 05:53

thomastedder wrote:Thank you. I'll go over there and check that. I've been looking for a book, but can't seem to find one.

Put it this way: I bought a Haynes 740/760 book and I can honestly tell you, the online 700/900 series FAQ + help from knowledgeable and generous Volvo DIYers from forums such as this one beats that unreasonably popular book hands down (the search engines in each forum is a big source of knowledge). I doubt the Chiltons book is any better. And there's strangely no Bentleys - which are tomes - for the 700 series or maybe I am wrong.

Myself, I am just a newbie trying to give back what I have learnt from others. Thus far, with a lot of online help and some common sense, I have replaced a distributor, changed the crankcase breather, and my proudest moment yet, all four brake rotors and pads including a Hobson's choice rebuild of the rear calipers + the emergency brakes. I am slowly fixing up my 740 for a 12,000km cross country drive.

I am trying to talk myself into letting a proper mechanic handle a kickdown cable replacement since it's going to be really messy

I reckon the only 700 series documentation worth buying are the actual Volvo service manuals.