Maserati Forum banner

1 - 20 of 35 Posts

·
Registered
Joined
·
93 Posts
Discussion Starter #1
I’m noticing GranTurismo sport differentials and Quattroporte Share part number 270983.

It seems cabrio and non sport models have differential 270982. Does anyone know the differences? Are they interchangeable?

Could it be the difference is the final drive ratio? Or just a measurement difference. I see Quattroporte of those years used to have a 4.1 final drive ratio and I thought all GranTurismos had a 3.73 final drive ratio. I’m wondering if certain years had different final drive ratios.
 

·
Registered
Joined
·
208 Posts
Yes they are. Just make sure the ratio is correct. They changed the ratio from earlier years, I am guessing from the 4.2 engine.
 

·
Registered
Joined
·
37 Posts
Interesting.......
A 4:10 rear would certainly get you out of the hole quicker
Wondering if the ring and pinion are interchangeable only , will have to do some research for part numbers
 

·
Registered
Joined
·
427 Posts
whoah - so the GT-Sport has an open diff? make no sense. My Sports Convertible has LSD, I imagine all SPORT/MC have the LSD?
 

·
Registered
Joined
·
208 Posts
whoah - so the GT-Sport has an open diff? make no sense. My Sports Convertible has LSD, I imagine all SPORT/MC have the LSD?
How did you get to that conclusion? My version ...82 is the lsd. Some earlier years had different ratio with open diff on the sports
 

·
Registered
Joined
·
650 Posts
as far as i understood, all diffs were limited slip at introduction of the ZF trans, 3.73 for GTs and 3.53 for QPs. the darkness of diff fluids that come out of every 139/145 without an F1 confirms this theory to me. open diffs don't shed any material to darken fluid to that degree.
983 lists granturismo sports 13 to 15 and MC 12-13. 983 also fits 9-13 QPs if you go back a few superseded part numbers of diffs. that part doesn't make sense in the parts look up since the final drives are supposed to be different.
982 lists for grancabrios 10-15. superseded part numbers don't show up at all for info.
my best guesstimate without having eyes on both, besides the drive ratios, is maybe a shape difference or mounting point difference due to the cabrio and coupe shape difference in the rear end. sub-frames are the same though.
 

·
Registered
Joined
·
1,552 Posts
If you don't see the old 10-bolt cover (open differential), you are most likely dealing with a LSD limited slip differential 99.9% of the time!
Open Differential.jpg
 

·
Premium Member
Joined
·
2,273 Posts
Damn dude, your Maserati looks very poorly maintained , get some Rustoleum and clean up that underside :LOL:😜

my 2013 Sport coupe has an LSD.
 

·
Registered
Joined
·
1,552 Posts
Damn dude, your Maserati looks very poorly maintained , get some Rustoleum and clean up that underside :LOL:😜

my 2013 Sport coupe has an LSD.
I'm on it!!! lol
 

·
Registered
Joined
·
208 Posts
In my search for the my 12 Cabrio,
How did the gears get chewed ?
I was doing 120-140 for about 20 min, then some hard launches back to back about 3-4 times and on the last brake hold (launched as per owners manual 😇) I accidentally launched from 5-6k rmp....it was also 100 degrees that day, I assume thing got extremely hot and heated. I normally launch into a nice slide but I guess I pushed it too much that day.

It took me 2 weeks to find the 82 diff, everyone (junk yards) will tell you they have it but that is not true they use the vin of the car and it will say ..82 but the actual part number is old with different ratio. I found 1 in the entire country. Not a hard job, can be done in under 2 hours.

............ oh and Jason saved me thousands in repair
 

·
Registered
Joined
·
93 Posts
Discussion Starter #18
I’m still confused because something doesn’t seem to add up.

It doesn’t make sense sport models didn’t come with an lsd but it does make sense that 82 is an lsd option otherwise the used market I don’t think would price it at that large of a premium over the 83. And I’m still not sure how to locate a 4.1 ring and pinion from a Quattroporte gt s which seems to be the same part number or why it would be a different ratio with the same part number if it is a different ratio than sport models at all.

In my search for the my 12 Cabrio,

I was doing 120-140 for about 20 min, then some hard launches back to back about 3-4 times and on the last brake hold (launched as per owners manual 😇) I accidentally launched from 5-6k rmp....it was also 100 degrees that day, I assume thing got extremely hot and heated. I normally launch into a nice slide but I guess I pushed it too much that day.

It took me 2 weeks to find the 82 diff, everyone (junk yards) will tell you they have it but that is not true they use the vin of the car and it will say ..82 but the actual part number is old with different ratio. I found 1 in the entire country. Not a hard job, can be done in under 2 hours.

............ oh and Jason saved me thousands in repair
my sources have been parts suppliers like scuderia and car and driver cross referenced against other websites. But something here or there is wrong. Maybe final drive ratio has to do with the manufacturer part number on the diff I’ve found a couple different ones like 3.33950.3, 3.51331.3 and not the part numbers we are discussing. Randy do you have any input on that how did you differentiate amongst ratio? That you referenced above. You also said both 82 and 83 in your research are the same external measurements is that correct?



I’ve also found another part number that some other website claim are relevant for certain years GranTurismo and Quattroporte 234007.

I will get my car on a lift in the next couple of days to see the part number it has and I will test for lsd by spinning the rear tires while in the air. So we can start to narrow it down a bit more and start to confirm some of this online info. Maybe we can get some clarification from the Quattroporte GT S owners as well.



 

·
Registered
Joined
·
427 Posts
Ya, it make zero sense to me that they give the Convertible Sport an LSD, but NOT the coupe. My sport def has LSD, I see it when the car is on the lift, but more importantly - DAYM does it make this 4800lb cruiser rotate!
 
1 - 20 of 35 Posts
Top