As the weather has turned cooler, I notice that the Transmission is slow to shift out of first, and maybe second gear for the first minute of driving or so. It does not feel like it is slipping - just holds off shifting till rpms go up and maybe I let off the gas. It acted this way on a couple of ocasions last winter, but only when the weather was below zero. Now it is acting up in moderate weather (40 degrees F).

Over the years I have followed with keen interest the debate regarding flush/no flush philosophies. I don't know the right answer, but have decided to change the fluid to see if it will fix the slow shift problem. I checked bay13 and searched the archives and have seen conflicting answers to this simple question:

When flusning the transmission by disconnecting the top hose into the cooler, does the fluid pump out of the top hose, or out of the top fitting on the radiator?

The car has 160K and this will be the first flush. What non-synthetic fluid is recommended? May upgrade to synthetic at a later date.

TIA

Dan

while flushing your tranny is a very good idea, your problem might not go away. it is very possible that your pnp switch might need changing very very soon.
regards

I am sure you are right. I puled the codes today and got 3-1-3 from socket position A1-- PNP switch.

Last evening the Check engine light came on and I got 2-4-1 from socket postion A6 -- EGR system flow fault. Guess I'll clean the egr valve when I have a bunch of stuff out of the way to replace the PNP switch.

Dan

Thanks to you all.

Dan

Dan,
I strongly suggest that you look at the alternate method and use the upper hose.
It is much easier to reach and you do not have to remove and replace the battery several times ( to start the car to pump fluid). Many of us have used the upper hose with a 1/2" ID hose over the end for a drain with good results. The concerns voiced about flushing the cooler can be addressed by blowing it out with some low pressure air blown into the cooler where you disconnected the upper hose. Do this before starting the flush cyle. The fluid in the cooler will join the fluid you are pumping out of the sump. BTW, getting a wrench on the lower hose connection on the tranny can be a PITA.

Larry,

You are correct about the extra effort to remove the battery for accessing the lower hose. I always use the lower hose method with the battery outside the car. I used a jumper cable to connect the battery outside the car and the battery connectors under the hood. All you need is the 22mm crowfoot wrench with an extension and a 22mm open box wrench to unloose or tighten the lower hose union nuts. It is not that difficult. If people think this is too much work to do, then go with upper hose. I use this method because Volvo shop manual lists this way to flush the tranny. I don't mind doing this extra work. YMMV.

Ching-Ho Cheng
--
1995 855 NA, Bilstein Strut & Shocks, Volvo Protective Grill, K&N Filter, E-Code Lens, Alpine CD-Changer, AutoDim RearView Mirror, 6000K HID

I use a non syn atf with Dextron in it. Chevron I believe.

Flushing the fluid from the top hose is much easier then from the bottom hose. However, the fluid in the cooler in the radiator isn't flushed. I poured fluid into the top of the cooler and was able to flush it. It was easy because I had installed an in-line filter some time ago so I had something to attach a hose to in order to pour fluid into it.

Good luck.
--
Don 93 & 95 854 GLT, 95 855T

Dan,

Well, the flush is definately a good thing since it will be the first, but the PNP switch is notorious for starting to fail when the weather gets colder.

If you go out tomorrow morning, put the shifter in 3 instead of DRIVE and see if the shift is normal.

When my switch was dying, there was no code and several mechanics said I needed a new tranny. I new nothing was wrong with the tranny and then I found this site and read about others that had the same problem.

It'll get worse and will seem like it'll never shift out of 1st (until it really warms up). If you get the RPMs real high and it still won't shift, you'll likely get the "arrow-up" on the dash to appear and then the tranny will go into safe mode. It'll feel like you're starting off in 3rd gear instead of first.

I'll bet it's the PNP/neutral safety switch.

Thanks for the tip on the PNP switch. I'll search the archives and bay13 to see if this is something I wish to tackle.

Not sure of all the functions associated with the PNP switch. I guess I thought it was like the neutral safety switch on the RWD Volvos. Any idea what PNP stands for?

I may have to wait a day or two - warmer weather here for a few days.

Thanks much for your advice.

Dan

PNP - Park Neutral Position switch.

I used the lower hose to flush my 855's tranny. It is more involve in terms of component removal/installation, but it also flush the radiator cooler. I use Mobil 1 ATF.

Ching-Ho Cheng
--
1995 855 NA, Bilstein Strut & Shocks, Volvo Protective Grill, K&N Filter, E-Code Lens, Alpine CD-Changer, AutoDim RearView Mirror, 6000K HID

Hi HO (sounds funny doesn't it). I'm going to change the fluid in a '98 S70 soon using the procedure in the Haynes manual which means disconnecting the bottom hose. Is there a washer associated with the union on the bottom hose that should be renewed??

Cheers, phil
--
'98 N/A S70 130,000 Klm

Phil,

People do call me Hi Ho :-) The Haynes manual procedure was the Volvo repair manual's procedure. The union nut (on the tranny) of the lower hose is 22mm in 850. There is no o-ring/washer in the union nut. I used 2 22mm open end wrenches (one of them is a "thin" open end wrench) to unloose or tighten them. I hope that S/V70 use the same size union nut.

Hope this help

Ching-Ho Cheng

--
1995 855 NA, Bilstein Strut & Shocks, Volvo Protective Grill, K&N Filter, E-Code Lens, Alpine CD-Changer, AutoDim RearView Mirror, 6000K HID

Well I did the tranny flush today using the bottom hose method as detailed in the Haynes manual and found it very easy. You don't have to remove and install the battery multiple times at all and it is a good time to clean up the battery tray and check the connections on the cruise control as it is located under the battery tray in the S70. I don't know why the plastic cover under the radiator had to be removed or the car jacked up as recommended in the manual. Doing it again I wouldn't bother with these 2 steps as detailed in the manual. In all I used a total of 10 litres of fluid, and even though the transmission was shifting very smoothly before, I can certainly notice an improvement following the flush. A 1/2 inch ID hose is pushed onto the end of the hose which is unscrewed from the union on the transmission housing and is held in place by screwing the union nut onto the outside of the house - very neat and reliable. When you see bubbles in the clear plastic hose stop the engine and add 2 litres of fluid into the dipstic holder. Repeat the process as per the manual until the fluid runs the same colour as the new stuff. Very simple and straightforward. Also replaced the engine oil, filter, drain plug washer, cleaned the flame trap (wasn't one) and the throttle body so it was a very productive weekend.

Cheers,

Phil
--
'98 N/A S70 130,000 Klm

fluid comes out of top hose into radiator cooler. Have a new hose fitting clip on hand in case you damage the old one when you remove it.
--
'88 240, '92 740, '98 v70 GLT John in Tampa Bay

John,

Thanks for the quick answer. I bought a clip a while back, and may stop by to pick up an o-ring before removing the hose.

Any recommendation on fluid?

Dan