GT 3.2 calibers to 156 2.5, chain of changes... - Alfa Romeo Forum
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GT 3.2 calibers to 156 2.5, chain of changes...


I am about to acquire a lovely well maintained alfa 156 ti SW. The car has had the engine changed to a 3.2 with some additional tuning. A real Q car. The brakes shall of course match the power, and a pair of 330mm brembos from a GT 3.2 have replaced the standard brakes. The change of calibers went along with the change of the suspension struts, as advised in the general fora.

It turned out the connection of the steering rods did not allow for proper wheel alignement, in fact some 20-25mm are missing. This is the current status, with the car on the lift, and a surprise.....

Advice on how to proceed is appreciated. I have collected the following information, which I hope to have comments on:

- The front suspension of the GT 3.2 is similar to the 147 GTA
- The track width front is 1524mm for the GT 3.2 and 1511 for the 156 2.5
- The gearing of the steering rack of the GT 3.2, 147 GTA and 156 GTA is 1,75 turns lock to lock. For the 156 2.5 it is 2.1 turns.
- The steering column of the 156 is different from the steering column of the 147 / GT
- Further a 156 GTA is available as a possible doner (305mm discs).

Assuming the above, the following opportunities present themselves.
- Undo the change (not first on the list of options)
- Change the steering rack, from the GT (not preferred, expect further problems with the steering column)
- Have special longer track rods manufactured (not liked)
- The track rods are reportedly longer (235mm versus 218mm) on the GTA. The donor GT track rods are same length as the original 156 2.5. (Perhaps the solution)
- or alternatively, advance with the spares from the 156 GTA instead:

Are there anyone with experience changing the steering rack from the 156 GTA to 156 2.5?
Would this (possibly) solve the problem (with the bonus of the direct steering)?
Or will the struts from the 156 GTA with the 305mm discs actually fit the 330mm brembos? or should I settle for the 305mm disc from the GTA and that would then be it?

The matter is now sent to the world wide expert team members, with the car waiting on the lift.

Many thanks in advance, from South Africa.

Last edited by 156swti; 30-07-16 at 19:36.
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The 3.2 GT and the GTA's use virtually the same suspension. I think the only difference is the rear anti roll bar on the GT is slightly softer.

The 330's and the 305's use the same upright. There are no compatibility issues when swapping between the two, assuming of course you have the mounts for the 330 callipers.

The 3.2's use a different hub and outer cv joint. You have a few options in respect of this;

1. Source and use GT 3.2/GTA outer cv joints with the v6 drive shaft and inner joint. Sourcing the CV joints will be difficult.

2. Hope that the brakes and uprights come with 3.2 drive shafts.

3. Use the 2.5 hubs in the 3.2 uprights. The wheel bearings are the same but you'll need new ones. It's also highly likely you'll need new abs sensors as they need to be removed to get the bearings out and they nearly always break.

And as has been mentioned, you'll need longer track rods. 3.0 v6 166 track rods are the same as the GTA and GT ones.

I wouldn't bother with the steering rack.
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