Rear end alignment

[Starter986]

I was watching a youtube vid... transmission removal (I was bored. Will not be removing my transmission).

As the fellow was removing the 2 bars and the metal plate, under the transmission, he mentioned that removal of the bars, and particularly because of the bolts (not nuts) at each end of those bars (closest to the under the back of each door) that an alignment would be necessary once everything was buttoned back up. He mentioned that thse 2 bolts are associated with the rear alignment adjustment.

Is this correct? I'll be doing the transmission fluid drain... new filter... clean pan... etc... and would like to know if when completed I'll have to take it in for a rear end alignment. What would be a ballpark price on that task? Should I consider a 4 wheel alignment?

Thank you.

[The Radium King]

well, camber is set by eccentric bolts on the lower control arms, and toe is set by eccentric bolts on the toe control arms. caster is not adjustable. these are your alignment variables. now, the lower control arms and the toe control arms attach to the rear subframe - this is a big bracket on each side of the car where the tops of the brackets are bolted to the frame and the bottoms are bolted to - all those bars and plates you are referring to.

so, if you were to remove the bars and plates, there is a small chance that the bottom of the subframe would move and affect alignment settings. the thing is, when you put them back in place things will pretty much go back to where they were. so, need to redo alignment? probably not. i think a lot of transmission undertrays have come on and off over the years without a follow-up alignment.

[Starter986]

Originally Posted by The Radium King

well, camber is set by eccentric bolts on the lower control arms, and toe is set by eccentric bolts on the toe control arms. caster is not adjustable. these are your alignment variables. now, the lower control arms and the toe control arms attach to the rear subframe - this is a big bracket on each side of the car where the tops of the brackets are bolted to the frame and the bottoms are bolted to - all those bars and plates you are referring to.

so, if you were to remove the bars and plates, there is a small chance that the bottom of the subframe would move and affect alignment settings. the thing is, when you put them back in place things will pretty much go back to where they were. so, need to redo alignment? probably not. i think a lot of transmission undertrays have come on and off over the years without a follow-up alignment.

Thank you, RK. That make sense.

I figured that if the car were up on 4 jacks... and not moving around... nothing could really get out of "whack", necessitating an alignment. Now...

Before I tackle the transmission fluid I'm going to drain, flush, and refill the coolant. In an effort to retrieve all the old coolant, after first warming up the car with the heater on, I was going to slightly lower the rear end to encourage the coolant to follow gravity. Further, as I fill the coolant back up... I was going to lower the front end to encourage air to follow the path of least resistance. Do you believe that front/rear lowering will cause enough shift to reconsider an alignment (again, when everything is buttoned up)?

Finally... all 4 wheels are on the car... and unsupported. Will that cause a strain on any suspension parts or the axles? Should I remove the wheels? Likely I'll have the car on stands for the next month.

Thank you, again, for your consideration.

[Starter986]

Originally Posted by Starter986

Thank you, RK. That make sense.

I figured that if the car were up on 4 jacks... and not moving around... nothing could really get out of "whack", necessitating an alignment. Now...

Before I tackle the transmission fluid I'm going to drain, flush, and refill the coolant. In an effort to retrieve all the old coolant, after first warming up the car with the heater on, I was going to slightly lower the rear end to encourage the coolant to follow gravity. Further, as I fill the coolant back up... I was going to lower the front end to encourage air to follow the path of least resistance. Do you believe that front/rear lowering will cause enough shift to reconsider an alignment (again, when everything is buttoned up)?

Finally... all 4 wheels are on the car... and unsupported. Will that cause a strain on any suspension parts or the axles? Should I remove the wheels? Likely I'll have the car on stands for the next month.

Thank you, again, for your consideration.

Bump Bump Bump

[Quadcammer]

Your alignment will be fine.

Its not great to have the car off the ground for a month, but you'll likely do no damage.

The coolant drain is on the bottom of the engine, no need to lower the rear. The car has like 6 gallons of coolant, so not getting a few liters out is no big deal.

i would however drop the front when you are filling to help with bleeding.

[Starter986]

Originally Posted by Quadcammer

Your alignment will be fine.

Its not great to have the car off the ground for a month, but you'll likely do no damage.

The coolant drain is on the bottom of the engine, no need to lower the rear. The car has like 6 gallons of coolant, so not getting a few liters out is no big deal.

i would however drop the front when you are filling to help with bleeding.

Thank you. I've a new plug for the coolant drain.. and will be loosening some hoses... and I'll be tackling the motor mount while I'm down there... and coincident the water pump... low temp thermo.

I will be dropping the front end to ensourage out the air. Thank you.