Engine 850: B5234T/2.3/20v/T5: Manual Transmission Swap

[stevepcar]

The Auto box on my 1996 T5 needed replacing so I swapped it for a second hand one. Its not given me any problems, until recently in a traffic jam, the change from 1st to second seemed clunky. I am tempted to swap it for a manual box, Robert DIY & Mathews Volvo site have good write ups on this. I have a donor car which is a 1996 2l manual, but the final drive ration as stated in the hand book is 4.45:1 on the manual, whereas the T5 would be 4.00:1 if it was a manual. Also the gear ratios differ from the Auto to manual.
I have 2-questions: 1: What effect would the different ratios have on the engine.
2: Would the rev counter & speedo reading be inaccurate if I do the swap. If so how could I overcome this.
Any help or advice as always welcome.

[Luxobarge]

You'd have a car that revs far more than it needs to in top gear, so limiting top speed and probably giving poor economy on a run. It would accelerate fast, but I would have thought that it would be hard to live with.

Rev counter is driven from the crank sensor so would be unaffected, and speedo is driven from the front left ABS sensor, so would also be unaffected.

[VerdeV70]

Originally Posted by stevepcar

The Auto box on my 1996 T5 needed replacing so I swapped it for a second hand one. Its not given me any problems, until recently in a traffic jam, the change from 1st to second seemed clunky. I am tempted to swap it for a manual box, Robert DIY & Mathews Volvo site have good write ups on this. I have a donor car which is a 1996 2l manual, but the final drive ration as stated in the hand book is 4.45:1 on the manual, whereas the T5 would be 4.00:1 if it was a manual. Also the gear ratios differ from the Auto to manual.
I have 2-questions: 1: What effect would the different ratios have on the engine.
2: Would the rev counter & speedo reading be inaccurate if I do the swap. If so how could I overcome this.
Any help or advice as always welcome.

I haven't done an Auto to Manual change but I have had some indirect experience with changing the final rations in a manual box.

1. I don't think there would be any difference to the engine. It may have to work harder depending on the gear that you are in, for example accelerating from 30 in 5th. It will do it, but the car has to work harder than if it was doing it in 3rd due to not having the revs in the peak power band. Someone may be able to offer more of an explanation than I can, but I don't see there being any issues. The T5 was designed to run both manual and auto.
2. The rev counter shouldn't have any issues and nor should your speedo. The speedo is taken from the front right sensor I think on the wheel. The only thing that would affect it would be tyre size. The rev counter measures direct from the crankshaft.

[stevepcar]

Thanks for your useful advice, I do have one other question: There are a collection of wires that go into a connection on the auto box, that Robert in his video just cuts off and does not offer any further info on. Does anybody know which of these are needed to be reconnected to anything else please?

[CNGBiFuel]

I can't tell you anything about the swap itself... instead, I'm going to assume you've flushed clean ATF thru' there and shoved in a Magnefine long since? If not, and you've not let things continue for too long, you could well save yourself the hassle. More so, if like me, you like an auto anyway. Often it's low fluid levels, I'm not alwasy sure soem were ever right from the facotry, because I've found them low, when they're not leaking. Getting the fluid level correct is a real faff.

The fault you describe is usually clogged solenoids/ burnt fluid., and if you've not fitted a cooler, it will be burnt. Clean fluid and a filter often clears it.

[stevepcar]

Thanks ref the Magnefine filter, do you know what size would be required for the 850 T5 and where I could get on in the UK please? I have seen 3/8" & 1/2" on ebay, but not sure what size is required. Also where should it e fitted. I drained the second hand box when I got it & added new fluid a litre at a time, whilst the engine was running, that was about 1500 miles ago, so I am going to flush it again. I should have changed the existing filter too, which I will also do.

[CNGBiFuel]

Mine's 3/8 ( 5 speed 1999 car) , however the early boxes are 1/2". Fittings are different on early stuff, how this differs exactly I can't say, I've never done a 1/2".

I'm banged on about this in numerous threads, flush fluid every 25-30K or fit a cooler. Don't let it go brown. If it's not pink/bright Red, when you wipe dipstick on paper towel, flush. If it's bropwn it's Bisto, not ATF.

If you wish to keep it pink fit a cooler or flush regularly. Magnefine keeps the crud out of the valve-body solenoids. Fresh fluid washes old crud out, but if it's gone too long,, you might get away with cleaning solenoids. A pain to do, with variable success, more likely - goodbye box.

eBay is where I get mine, imported variously from US or Aussie. If you can get it, old design is better - bigger magnet. The Yanks get these for about a tenner, you won't.

Level is critical. The only accurate way to get it right is at 85•C which is a pig to sustain for tests.

[winsox]

Originally Posted by stevepcar

The Auto box on my 1996 T5 needed replacing so I swapped it for a second hand one. Its not given me any problems, until recently in a traffic jam, the change from 1st to second seemed clunky. I am tempted to swap it for a manual box, Robert DIY & Mathews Volvo site have good write ups on this. I have a donor car which is a 1996 2l manual, but the final drive ration as stated in the hand book is 4.45:1 on the manual, whereas the T5 would be 4.00:1 if it was a manual. Also the gear ratios differ from the Auto to manual.
I have 2-questions: 1: What effect would the different ratios have on the engine.
2: Would the rev counter & speedo reading be inaccurate if I do the swap. If so how could I overcome this.
Any help or advice as always welcome.

hello there

I have done the swap myself and the Speedo comes from the ABS module and the Revs from the ECM so these should not be effected. (well least on my 1996 850r)

However I would strongly recommend changing or programming the engine management for a Manual Box as when you take you foot off the gas its jurks the engine due to the fuelling I think.

You will need to link out 2 wires from the PNP switch on the selector and wire another 2 from there to the reverse switch on the manual gear box

[CNGBiFuel]

If all else fails - it's been 'flaring' for too long?.... then it's getting increasingly unlikely you'll source a good replacement auto, hence a manual conversion is the more viable option.

I've been lucky, fresh fluid changed often, a cooler and in my case a Derale stat on there too. Catch it early and you'll be fine.

https://www.volvoforums.org.uk/showthread.php?t=235190

Catch it at 90K. If you've allowed black/brown fluid much over 140,000 you may still get away with it, yet likely it's too late.

Heat kills auto transmissions, if yours has been a London car, with no cooler, knock 30K off.

[stevepcar]

Originally Posted by winsox

hello there

I have done the swap myself and the Speedo comes from the ABS module and the Revs from the ECM so these should not be effected. (well least on my 1996 850r)

However I would strongly recommend changing or programming the engine management for a Manual Box as when you take you foot off the gas its jurks the engine due to the fuelling I think.

You will need to link out 2 wires from the PNP switch on the selector and wire another 2 from there to the reverse switch on the manual gear box

Thanks for this useful information, but I could do with a bit more guidance on the wiring. When you say link out 2-wires from the PNP switch, what do you mean, is that join them together, or should they just be terminated, secondly do you know which wires need to go to the reversing switch please, thirdly will any of this affect the cruise control? Any advice welcomed.