Volvo 740 Overdrive problem (common, it seems!)

[RavenT]

Originally Posted by Jonny Jones

Hi people,

Ive been searching/browsing numerous topics relating to intermittent overdrive. I'm having the same problems on my 1989 740. When the engine is cold and when I'm driving, it engages bang on when you hit the button on the gear stick - a very positive gear change into 5th. When the engine is fully warmed up, it only engages at 60mph or above, the '5' light comes on but hangs for a while before changing when you reach 60mph. However when you've been driving a while and traveling around 70+ (mainly accelerating, overtaking etc) in 4th, it will sometimes not work at all - ie you will push the button, but the '5' light doesn't come on and obviously overdrive doesn't engage - so you end up screaming along in 4th gear! When this has happened in the past (today infact) I've been sat there just pushing the button hoping it will engage with the next push of the button haha, however it does engage... when it feels like it! So all in all, a very temperamental overdrive! Very annoying too!

I think I've read similar problems but this is the extent of the problems I am having with my 740's overdrive. Do people think its purely the electrics at fault or do you think its maybe because the tranny oil hasn't been changed in a LONG time? Its just the whole cold engine instantly engaging then hot engine not engaging until 60mph+ etc that baffles me.

Many thanks in advance for any help and advice!

P.S. - Thought Id mention, its a 2.3 Petrol Manual. B230E.

On my 740TD, also intermittent operation. It was some cracked solder connections on the O/D relay. Replaced. No problems since.

RavenT hants

[telmo]

Forgot to tell my experience. After two oil changes, the OD gear up didn't totally clear up the symptoms as described Jonny Jones...Got much better, though!
If very warm engine or hot weather, only if revving above 3000-3200rpm in 4th it engages totally the OD ("5" lits but no pulling).
Seems I have worn friction discs. I can live with that for several years to come...

[Jonny Jones]

Originally Posted by telmo

Whenever you change gearbox oil, do not forget to remove the OD pan (just need silicon to fit in place), this comes with lots of debris and mud from the system.
Beware of the correct new fluid (see other posts or FAQ for this subject) for the M46 gearbox.

Bit of a bump! OK I've decided to tackle all the servicing for my 740 this coming weekend. Im doing engine oil, tranny oil, plugs and of course engine oil filter + air filter.

GSF have said that I will need F_uchs (forum thought it was a swear word!) Titan XTR 5W-30 for the transmission oil - its a manual by the way. Does this sound right?

Also, does anybody know how many Ltr's of tranny oil I will need? Any help and advice would be much appreciated!

[nickm]

The M46 manual transmission uses AFT type F, not normal gear oil, auto transmission fluid. Others might chime in if the type you quoted is Ok.
It's bit over 2 liters. Fill it to the top of the filler lug.
Nick

[Jonny Jones]

Originally Posted by nickm

The M46 manual transmission uses AFT type F, not normal gear oil, auto transmission fluid. Others might chime in if the type you quoted is Ok.
It's bit over 2 liters. Fill it to the top of the filler lug.
Nick

OK great! I'll get them to check the oil grade as you've mentioned when I go and get it on Friday.

Is the tranny oil easy enough to change? Or is the filler lug hard to get to? The car wont be on a ramp, more likely axle stands.

EDIT: Did you mean ATF type F?

[nickm]

Yep
ATF type F.
I did this before installing the box so I can't comment on the difficulty redoing that, but looks pretty straight forward.
***HS (will not allow this name???) is an Australian company funny to be recommended that in the UK. I've used their engine oil it's fine before.

[Jonny Jones]

Originally Posted by nickm

Yep
ATF type F.
I did this before installing the box so I can't comment on the difficulty redoing that, but looks pretty straight forward.
***HS (will not allow this name???) is an Australian company funny to be recommended that in the UK. I've used their engine oil it's fine before.

Yeah F_UCHS is quite common over here in the UK. I noticed your 740 is a Turbo? (Going by the grille design) - im guessing my 740 2.3 (B230E) will have the M46 gearbox you mention - 4spd + overdrive?

Im heading to the store tomorrow after work to get all my stuff, so I definitely need the ATF Type F Auto tranny oil even tho its a manual. I know I'm repeating myself but I REALLY want to be sure! Thanks so much for your help mate!

[Jonny Jones]

Not to worry. The oil the guy said I needed, turns out Volvo UK don't recommend it. So I went with the ATF stuff! Thanks for everybody's help, fingers crossed things will go well tomorrow when I do the service - making it sound a big thing, probably isn't for a lot of people, but the garage has always done everything, but I want to learn