Lamborghini Talk banner

RWD diy with pics (and impressions)!

45K views 174 replies 55 participants last post by  robgreg75 
#1 ·
I finished the RWD DIY on my 05, and I am really happy with the results. I followed instructions from a couple different sources on this forum, but never did find a comprehensive, DIY thread with pictures, so I thought I would do one here for the benefit of folks like me that like a little more detail before diving in. If you can change your own oil, you can do this. I do recommend taking this on with a helper, however, as there are a few steps that are definitely easier with a second set of hands.

Step 1: Stuff you will need to Buy.

First, you need to source some stub axles to hold the wheel to the hub after the axles extending from the differential to the wheel hubs are removed. You can obviously buy the Balboni stubs ($$$) or one of the options available from various forum vendors/members ($). Based on a tip from a forum member I bought the following audi/vw units, which come with the entire CV Joint assembly, boot, and new axle bolt. You will need two, one for each side, but 48 bucks per side with free shipping is pretty hard to beat. Here is the part number and Amazon link:

8E0407452X - 1 Year Warranty - FEBEST # 1710-A4B6A45

Amazon.com: 8E0407452X - 1 Year Warranty - FEBEST # 1710-A4B6A45: Automotive

The new axle bolt that comes with the new stub axles takes a 27 mm socket, so you will want to source one before you start (found one at autozone for a few bucks). In my case, the OEM axle bolts you will need to remove required a 17mm allen socket, which I also found at autozone. See Pic 1. The only other “special tool” you may need is the triple square bit for the axle to differential bolts (see pic No. 2), but if you don’t have one you can use an 8mm allen bit (its not ideal, but it will work in a pinch. I’m not sure of the size of the oem bit needed as I opted to use my 8mm allen bit). The rest of the tools you will need are normal stuff that should be in any toolbox. Pic 3 shows the entire axle assemblies supplied by the above-vendor.
 

Attachments

See less See more
3
#30 ·
Nice tutorial! Thank you.
 
#33 · (Edited)
Removing the axles from the front wheels does not a 2wd car make.


"In order to shape this unique character that combines driving fun and safety, the engineers at Sant'Agata Bolognese have incorporated extensive modifications into the LP 550-2 Valentino Balboni. It was not simply a question of moving the transmission to the rear axle, the vehicle had to be adjusted and tuned in every element of its driving dynamics. This includes springs, dampers, stabilisers and even the tyres. The aerodynamics were also adjusted to take account of the change to the power flow.

The rear axle differential, with a 45 percent limited slip, was also redeveloped, as was the calibration of the e-gear transmission. One significant point was the adjustments made to the ESP system. While the standard program is focused on high stability, the CORSA program permits greater drift angles, thus enabling drivers to enjoy the dynamics of the LP 550-2 to their full extent."
 
#38 ·
Below is the factory quote.


"In order to shape this unique character that combines driving fun and safety, the engineers at Sant'Agata Bolognese have incorporated extensive modifications into the LP 550-2 Valentino Balboni. It was not simply a question of moving the transmission to the rear axle, the vehicle had to be adjusted and tuned in every element of its driving dynamics. This includes springs, dampers, stabilisers and even the tyres. The aerodynamics were also adjusted to take account of the change to the power flow.

The rear axle differential, with a 45 percent limited slip, was also redeveloped, as was the calibration of the e-gear transmission. One significant point was the adjustments made to the ESP system. While the standard program is focused on high stability, the CORSA program permits greater drift angles, thus enabling drivers to enjoy the dynamics of the LP 550-2 to their full extent."
 
#40 ·
So I have started this process today. First off. This job would suck without a lift lol. Just makes it so much easier to access everything. I pulled apart the CV joints in about 5 mins total. I didnt lube them up though and they still popped right out. Just didnt want the mess. Also. There are about 3 million screws to take off the underside trays so an impact cordless screw driver is a huge plus to have. The screws all have lock tight on them and are very tight at first. Im going back out tonight to work on it a bit more. Its fun. Will update once I get further. The nice thing was getting the panels off and seeing how clean this car was underneath. It obviously was never driven in much rain as everything is clean and all the bolts and screws have all come out really easy. Nothing is coroded or rusted at all which is a huge bonus.
 
#41 ·
Nice. I'm still loving this mod, although I'm going to move to 305 rears when the time arrived to replace the rear tires! Gonna lower and align next week.
 
#45 ·
Actually I would think the factory option would even be lighter as there is still one small drive shaft that comes out of the tranny that is not removable in this mod. I would guess if you removed that shaft and the coresponding mounting brackets and extra gears in the tranny to power that shaft etc you would probably save at least another 10 to 15 lbs. the factory must add some weight other places on the 2 wd cars.
 
#47 ·
Well I buttoned up the car and took it for its maiden voyage. First off its crazy that I could actually take it out this time of year where I live. Normally we would have 2 feet of snow and the roads would be solid ice and snow covered. So far this year we have only had about an inch of snow and the roads are bare and have not been salted yet this winter. First off is the steering. It's amazing. No more jerking and bucking when turning. The clutch engagement is quicker and seems smoother. Took it out on the highway and it's so smooth. 1st and 2nd gear will light up the the tires instantly but this is 100% because it was -4C (about 25f) and the tires are like hockey pucks. Once I got it out on the highway I opened it up a bit. Got up to 110 mph just to see how it felt. Was awesome. Anybody thinking about doing this don't hesitate. It's a great mod and is how the car should feel from the factory. I can't wait for spring now to take it out when the tires aren't hard as rocks. Going to be a long winter.
 
#58 ·
I thought about doing that too but after looking at them and realizing I might be saving another 1/2 lb at best off each stub I knew I would never be able to feel it or notice any difference so I just bolted them on and left it. Works great. You will love the feel once you get it done and drive it again.
 
#59 · (Edited)
I just came back from my machinist and couldn't be happier! He was able to remove a lot of weight out of these stub axles! He actually said that it wasn't easy since it looked like hardened steel! It cost me more than what I wanted but the $/lbs ratio is way cheaper than light weight wheels.



Sent from my iPhone using Tapatalk
 
#61 ·
Nice man. You are a man after my own heart. I would have done the same but it's a precision job as you don't want any imbalances that could cause a shimmy or wheel vibration.
 
#63 ·
What a real thing! Keep us in touch.
 
#64 · (Edited)
Scottslaw, thank you for the excellent write up!

A few comments:
In Step 6: I unbolted the front diff/driveshaft bolts first with the car in gear therefore no help was needed to press on the brakes.

With a small wrench I could access all the bolts without rotating the tires

Btw here are some extra pics of the bolts connecting the diff with the driveshaft for anyone thinking of undertaking this
Front diff

At this pic (top) you can also see the tunnel brace that I reused.

Rear diff


Step 7: For the axles I obviously needed someone to step on the brakes! Thankfully my gf had just finished working on her project and came to the garage to give me a hand

I was excited since I had already a set of triple square tools (NAPA P/N 10mm - SER2305) due to a previous Audi ownership - as is always the case the tool was missing but the regular to torx tool was fine


The diff wasn't as heavy as I thought! I was really scared since I was doing this by myself without a jack - none the less I was able to put it down safely without dropping it. Scottslaws advice on turning it clockwise (as you look the car from the front) was golden.

I know it might sound silly since the Gallardo is a stiff car but since I didn't want to lose any of the rigidity I replaced the brace that I removed when I took the diff off (this is the little brace connecting the two ends of the tunnel). I actually placed at the area where the middle of the driveshaft was since I felt that it would be better there (to prevent any flexing).



Probably this is unnecessary but I might try to source or fabricate another brace so that both are there (the second brace is welded on the driveshaft so I couldn't reuse it - see picture below)


Step 8: The front stub axles went in nicely



So far I'm extremely excited with the improvements in drive ability. Everything that I've read so far (and anticipating) was fulfilled! At parking lot speeds the car is completely transformed!
I didn't notice any difference in the front ride height (not at least something very significant)

Questions:
1) How is the LP550-2 tunnel - does it have the two little braces (where the rear of the front diff was and mid of driveshaft) or not?
2) How is the gearbox of the LP550-2? Does it have the axle moving the power forward? It actually hurts me (OCD anyone?) knowing that there is an axle moving aimlessly in my transmission (talking about the axle moving the power to the -now gone - driveshaft). Did the LP550-2 have that?



Sent from my iPhone using Tapatalk
 
Top