[AlfaOrjan]

Hello,

I have assembled the rear axle on my GTJ 1600 -75. The rear wheels seems to be offset sideways after measuring a bit roughly. 1/5 of an inch (5mm). Can it be the T-bar that needs to be adjusted? How can I check the correct position of the rear axle?

Regards
Örjan Åberg, Malmö/Sweden

 

[Joseph M.]

Some time ago, I checked the settings of the wheels and the (Alfa Romeo) garage told me that the rear axle was shifted 1 cm to the right (seen from the back). According to them, this was however within the factory tolerances and could be due to the bodyshell being hand built. They also said that they have seen several modern Alfa's with the same symptoms.

However I am very interested to know whether this can be remedied (if the deviation is not in the bodywork).

Joseph

 

[Andrew]

Some sideways misalignment is very common. I believe you can adjust some by moving trunnion shims under the rubber mounting bushing on both sides where it bolts to the body. Or alter the thickness of the plastic spacer between the mounting bushing and the end of the trunnion itself.

Andrew

 

[AlfaOrjan]

I have this topic on other forums, but with very poor reply. Talked with a friend who are quite experienced and he thinks that some displacement is to expect. I will consult the tire shop when adjusting the front wheel steering and return to this forum. Thanks for your reply.

Regards
Örjan

 

[60sRacer]

You can get a pretty bad offset if you put the trunion in backwards.

Robert

 

[Andrew]

Yes, some offset is normal; my 74 GTV had about .080" difference in the plastic shim size from side to side, which is not bad, but I look at an another 74 GTV last week that was off by about 2", which I'd say is too much.

Andrew

 

[60sRacer]

The flat side of the upper trunion of the differential housing is essentially on the centerline of the axle. if you flip the t-bar over and install it backward, you will end up with the axle mating to the wrong side of the t-bar; everything fits together fine. Just wrong. You end up with the axle very close to 2 inches off center!

BTW - the trailing arms also end up crooked by about their wqidth.

(Actually did this once when I put new bushings on the t-bar ends and got them in the wrong postiion for the bolt holes that mate to the body. Seemed to fit better in what turned out to be "backwards" position. Car drove wierd and it took quite a while to find the FUBAR.)

Robert

 

[AlfaOrjan]

You can get a pretty bad offset if you put the trunion in backwards.

Robert

What is the trunnion? I have some problem finding proper translation. Please specify.
Örjan

 

[60sRacer]

The T-bar at the top of the rear axle. Sorry about mixing terms.

R

 

[crashmctavish]

Misalignment from the factory is common. Drop the T bar out & shift or fit new shims to center it up. Its all in the manual, its particulally important with 7" rims!

 

[AlfaOrjan]

I checked the floor with a water level. Then 2 hanging nuts tied on each side of the car/chassis (beam above axle), so I could measure the distance from the inside of the discs to the strings. The offset was exactly the same as the offset outside on rims and rear fender. Pulled down the T bar and moved shims and managed to center it almost on the spot, referring to the strings. Now it looks better. Next is to consult the tire shop when adjusting the steering.

Regards, Örjan

 

[crashmctavish]

Nice one, good practical advice, you can also run a string around all 4 wheels with 1" blocks on the rears to account for the difference in track to give you a good idea of general alignment & the degree of toe in.