lookin for some info guys and gals ive not long bourght a 1988 325i sport due to the fact that i crashed my 1990 4dr 325i se (****) so my question is can i use the gear box from my moor door and swap it in to my sport because the problem is that they are both running dynoed at 210bhp but as the sport has close ratio box it aint got the legs like my 4dr and im a legs man yes the sports got the off the lights performance but come 3rd gear my 4dr will say good buy to most sports models you see i do a lot of motoway miles and the sport will run at 100 mph no props but it sits over 4000rpm but cams open so say good buy to the fuel were as my 4dr will sit at 100mph all day long at 3500rpm cams not open so i save loads of fuel so can i do a strait swap or is there any thing i need to do or know any help would be most greatfull many thanks and a happy new ......
scott..
gear box swap help
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luckyflush14
- E30 Zone Newbie
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Grrrmachine
- E30 Zone Wiki / Team Member
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Nice choice of cars, and good to know you're trying to fix one. Try and use the full stop button though, it hurts my eyes trying to read all that...
Anyway, to help; the Zone Wiki has all the info you need on gearbox ratios, so that you can compare your Moredoor to your Sport:
http://www.e30zone.net/e30zonewiki/inde ... in#Gearbox
If you were seeing a difference in RPM at 100mph between the two, that would be the differential rather than the gearbox; 4th and 5th gear is exactly the same ratio on the Sport and the standard 325i. So if your sport box isn't actually broken, you're a lot better off swapping the diff rather than the 'box.
And while the two boxes will bolt up perfectly, bear in mind that it's considered an engine-out job on these cars if you've not done it before; doing it on axle stands is a PITA, while the diff can be done by one bloke and some spanners in an afternoon, if needed.
The biggest downside of swapping your gearbox is, of course, that you're making your car a non-sport, and therefore it won't be worth as much when it comes to selling it on.
Anyway, to help; the Zone Wiki has all the info you need on gearbox ratios, so that you can compare your Moredoor to your Sport:
http://www.e30zone.net/e30zonewiki/inde ... in#Gearbox
If you were seeing a difference in RPM at 100mph between the two, that would be the differential rather than the gearbox; 4th and 5th gear is exactly the same ratio on the Sport and the standard 325i. So if your sport box isn't actually broken, you're a lot better off swapping the diff rather than the 'box.
And while the two boxes will bolt up perfectly, bear in mind that it's considered an engine-out job on these cars if you've not done it before; doing it on axle stands is a PITA, while the diff can be done by one bloke and some spanners in an afternoon, if needed.
The biggest downside of swapping your gearbox is, of course, that you're making your car a non-sport, and therefore it won't be worth as much when it comes to selling it on.
'89 325i Touring | Touring Resto Thread | In-Dash Screen install
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mrLEE30
- E30 Zone Team Member
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The gearboxes will swap with no issues, there are two gearboxes on the 2.5, the standard getrag 260 and the 260/5 or the "sport" box with a slightly lower ratio 1 2 and 3. But 4/5 same for both boxes. Sounds to me your difference is with the diff ratio.
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luckyflush14
- E30 Zone Newbie
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thanks lads . well it looks like ill be sticking with the sport box. im not swaping an lsd for an open diff.. ill just have to drive a bit slower on the motorways. mmm or just carry a bit more cash for fuel lol.. maybe ill get a different ratio lsd. we shall see but thanks for the quick responce cheers ... ps sorry for the poor spelling and gramer ....
if you do happen to change your mind on g=changing the box and diff you will need to change the prop too i've just found a new box for my sport which came from a 320 which is the same length and similar ratios but a standard 325 gearbox is slightly longer i believe as i measured one up all this can be done on the floor but it is a bit of an arse, i put mine on a spare set of 15's i had laying around as i don't think my mate would have apprieciated my sport on his ramp for 8 months!!!!
removing the diff isn't too difficult either but you would definatly need a trolly jack to lift it into place!
if your planning on keeping the car and you want a bit better economy then swap the box and diff over and swap them back when you sell it. you could look out for a better ratio diff for economy????
removing the diff isn't too difficult either but you would definatly need a trolly jack to lift it into place!
if your planning on keeping the car and you want a bit better economy then swap the box and diff over and swap them back when you sell it. you could look out for a better ratio diff for economy????