Alfa Romeo Forums banner

1 - 17 of 17 Posts

·
Registered
Joined
·
136 Posts
Discussion Starter #1
Can any one tell me if any of the Alfa 75 models had a LSD as standard fitment?. I had heard that some of the later 75's had the LSD from the factory. Next question; Is there any way to identify an LSD by doing a visual inspection while fitted in the vehicle?
Cheers & thanks
 

·
Registered
Joined
·
390 Posts
75 twinspark, 1.8t, 3.0 v6 all have lsd from factory,
there is no way i am aware of to tell from the outside, the only way to tell is to take off the inspenction cover on the side of the diff housing and have a look.
cheers, Brad
 

·
Registered
Joined
·
158 Posts
You can tell if it's got a good LSD, by turning the output on one side, by hand. If the output on the other side turns the opposite way, you have either a stock diff or an LSD that needs rebuilding, if they both turn the same way, you may well have a good LSD. Unfortunately, an LSD would only have to be a bit worn out to act like a standard diff in this way.
 

·
Registered
Joined
·
1,330 Posts
I had asked a similar question here, in the past. And got similar feedback.

I was told that there are no identifying numbers cast into the casings. And that cracking the cover to peek was the best test. So that test that fatdarryl proposed could be helpful too. If you had your answer by twisting the shaft, you wouldn't have to go the extra mile. If it wasn't conclusive, you'd still have to peek inside the cover.

I have a transaxle that came with a 3.0 Verde engine. Supposedly from the same car. I found that there were easy ways to check to see if the motor was truly a 3.0, in the stamped-in numbers and raised cast indica. But not so obvious on the LSD transaxle. So, I will probably have to do both of the above to know for sure, before I make the decision to pop that into my GTV6 project.

Another detail that popped up from my earlier query (and don't take this as gospel, as I'm no expert in this area): The Verde came with a full LSD differential, whereas the Platinum had a partial LSD design. I was told that anyone looking to do some serious racing would prefer the Platinum over the Verde.

Maybe someone else can offer insight as to why this might be the case.

Peter
 

·
Registered
Joined
·
172 Posts
that correct i believe the verde is a 3.5 and the other models are 2.0 LSD. Or somthing lol but yes the verdes have the big LSD on them.
 

·
Registered
Joined
·
4,090 Posts
The internal workings of Verde and Platinum LSDs are the same, i.e. same LSD function. The final drive ratios of the transaxles are different providing the Verde with lower highway cruising RPM. Hence, for faster acceleration and track/race cars people sometimes put Platinum transaxles in Verdes, but LSD functionality is the same.
Jes
 

·
Registered
Joined
·
172 Posts
thank you for making that clear now i understand...as i obviously didnt before.
 

·
Registered
Joined
·
1,444 Posts
Can any one tell me if any of the Alfa 75 models had a LSD as standard fitment?. I had heard that some of the later 75's had the LSD from the factory. Next question; Is there any way to identify an LSD by doing a visual inspection while fitted in the vehicle?
Cheers & thanks
The Auto 75's also came with an LSD but with the tall final drive.
 

·
Registered
Joined
·
136 Posts
Discussion Starter #9 (Edited)
Thanks guys. I'll do the output shaft test and see if that will shed any light on the situation. How can I tell the difference between the Verde and the Platinum models?.. This one is a 1990 model. I'd like to do some competition use with the car and so the lower final drive ratio would be better. Perhaps a better question is , can I check the final drive ratio via an Alfa dealer using the vin number?

One more quick question: planetmojo mentioned there is an easy way to confirm it the motor is a 3.0L by looking at specific cast numbers. Can anyone tell me what I should be looking for?.

Thanks
 

·
Registered
Joined
·
1,330 Posts
Hi Patanga,

The quickest way to check to see if the motor is a 3.0 vs a 2.5... I believe on the rear of the motor (near where the heads and block come together) there is a large raised '3.0' standing out from the casting. I don't remember if this is on the head, or on the block. But, in that area. You may need a mirror to see this if the motor is still in the car.

There is also a flat section on the block where you'll find something like a serial number. This is stamped INTO the metal (not raised), as tho you were marking something with a hammer and a drift. The numbers are different for 2.5s and 3.0s.

Sorry if the above is a little vague. If you still have a problem solving this... let me know. I have a 2.5 and a 3.0 Verde motor, both out of cars, and in different locations. Both are about 15 min drive each way, but I can get you more detailed info, if needed.
 

·
Registered
Joined
·
1,330 Posts
One question that a couple of us may have in addressing the gearing on Platinum vs Verde:

Since the gearbox and differential are separable... is it that the ratios in the differentials are identical, and the ratios in the gearbox are different?

I've overheard some chatter that racers are looking for an LSD differential, and also looking for a gearbox from a GTV6 with lower gearing. So they can get the best of both worlds.

On GTV6s, they changed those ratios almost every model year. From my experience, the 1983 models came with the highest gearing (better for top end, gas milage, and quiet ride). The 1984s had the lowest (when cruising on the interstate, you felt like you needed one more gear to shift into). But the '84s had better balls in pure acceleration.

So, that may answer some of your question. If the LSD diff is mated to a 1984 GTV gearbox... you may end up with your dream combo? Those with more expertise in this area are welcome to correct me, if I'm off target here.
 

·
Registered
Joined
·
3,810 Posts
Thanks guys. I'll do the output shaft test and see if that will shed any light on the situation. How can I tell the difference between the Verde and the Platinum models?.. This one is a 1990 model. I'd like to do some competition use with the car and so the lower final drive ratio would be better. Perhaps a better question is , can I check the final drive ratio via an Alfa dealer using the vin number?

One more quick question: planetmojo mentioned there is an easy way to confirm it the motor is a 3.0L by looking at specific cast numbers. Can anyone tell me what I should be looking for?.

Thanks
There were no 2.5s sold in Australia by 1990 as far as I know, so it would be a 3 litre. If the exhaust exits on the right hand side that would confirm it, along with the larger fuel tank that fills the back half of the boot. It should have "75 3.0 V6" badges on the right of the boot lid and no cloverleaf if it is a standard 3 litre and a 3.54 LSD diff. The high performance Potenziatas like mine have the badges on the left with the green cloverleaf, darker seat material, leather gear knob and steering wheel, Motronic injection with crank angle sensor and a 3.73 LSD diff. The engines have the hot cams and 10:1 pistons. See the picture below of my black Potenziata. The 2.5 cars had a centre exhaust like the twin sparks and a flat boot floor. They didn't have the concertina bumpers and body kit either.
 

Attachments

·
Registered
Joined
·
1,444 Posts
Patanga - the Verde / Platinum question that is a US market thing. Zero relevance to Australia other than interest factor.

Suggest you post a picture of the car and we can most likely tell you quickly what specs it would have had ex factory. I wouldn't bother asking a current dealer unless they have a particular interest in these cars
 

·
Registered
Joined
·
136 Posts
Discussion Starter #14
Ok That solves the Verde /Platinum mystery. Thanks. I've got a photo of the boot badges and the interior that might help to identify the model. It also has the consertina piece on the bumpers.

 

·
Registered
Joined
·
1,444 Posts
Looks like a standard 3 litre so would have come with an LSD and the tall diff.

Unless someone has rebuilt the LSD though you'll probably find by now that it's not doing much. Find a quiet wet surface, put full lock on, accelerate slowly in second to get moving then hit the power. With a working LSD you'll rotate. With a dead one or none at all the inside wheel will spin.

Pretty rough old test but works......:)
 

·
Registered
Joined
·
276 Posts
Looks a similar age to mine, which is a 3/89 build, 3/90 Australian complied, non-Potenziata 3.0.

But mine has the tail lights with red horizontal stripes through the clear lenses.

:)
 

·
Registered
Joined
·
3,810 Posts
The photos seem to have disappeared patanga. Can you re-submit them? You can attach them to your post.
 
1 - 17 of 17 Posts
Top