Ford mondeo allignment

[Tony]

The sub-frame bolts are stretch bolts so they should be replaced.

[mac]

The sub-frame bolts are stretch bolts so they should be replaced.

 

cheers tony. thought you would know. Is this a common problem for the bolts to stretch too far? would you recommend changing the bushes as well? Just out of curiousity are the bots on the rear subframe stretch bolts as well?

 

cheers for all your help.

[Tony]

Front/ rear sub-frame bolts are stretch bolts. In truth i wouldn't replace the bushings unless there is visible reason to do so. Look outside of the box and assume your returning complaint is for whatever reason the anchor bolts have come loose, address the immediate complaint and go from there.

 

FYI in all my years i've never had to replace the front sub-frame bushings.

[mac]

Front/ rear sub-frame bolts are stretch bolts. In truth i wouldn't replace the bushings unless there is visible reason to do so. Look outside of the box and assume your returning complaint is for whatever reason the anchor bolts have come loose, address the immediate complaint and go from there.

 

FYI in all my years i've never had to replace the front sub-frame bushings.

 

 

cheers

 

i spoke to the guy on the phone and the said its either the bolts or the bushes as the subframe is in good condition. im guessing it would be quite to replace the bolts one at a time as there are four. im looking for some literature on stretch bolts as they are new to me and i would like to understand their operating concept, havent been able to find anything decent yet.

[Tony]

Critical components have to be bolted on like any other but rather than just material torque these bolts stretch so being a memory metal there's constant tension keeping the bolt tight. Not the best explanation but it's the best my language can manage.

[mac]

Critical components have to be bolted on like any other but rather than just material torque these bolts stretch so being a memory metal there's constant tension keeping the bolt tight. Not the best explanation but it's the best my language can manage.

cheers tony

 

I have had the subframe down a couple of times and my research tells me that strictly speaking these bolts are one use only. am i right in thinking its quite simple to replace them through doing one at a time and then possibly doing an allignment afterwards? Is there any need to to drop the subframe, the guy was saying that he would like to take the subframe down to clean the area where the bushes sit into, any merit in taking the subframe down at all?

 

Thanks

[Tony]

Stop worrying about the bushings, these would need to be in a desperate condition that would be detected way before you post here. The sub frame bolts need to be replaced and the locating points need to be established during the process.

[mac]

Stop worrying about the bushings, these would need to be in a desperate condition that would be detected way before you post here. The sub frame bolts need to be replaced and the locating points need to be established during the process.

 

 

so subframe doesnt need to come down?

[Tony]

No, just replace the bolts and be sure the frame is located correctly.

[mac]

tony

 

is it possible to tell while doing a 4 wheel geometry if the chassis is twisted? and if so down to approx what tolerance?

 

Cheers

[Tony]

Measuring the body height on each corner is a clue as is if there's a massive difference in the front SAI positions.

[mac]

Measuring the body height on each corner is a clue as is if there's a massive difference in the front SAI positions.

 

 

thanks tony

 

body height differs by no more than 3mm when pressures are right.

 

(so kpi + camber = included angle, i think) for which have values from previous allignments and they always came out ok.

 

if say i had measurements from a fixed point back right to front left on the chassis and same on the other side, what in your experience could be the max value allowed (mm) before any detrimental effects were caused?

 

thanks again

[Tony]

Measuring the body height on each corner is a clue as is if there's a massive difference in the front SAI positions.

 

 

thanks tony

 

body height differs by no more than 3mm when pressures are right.

 

(so kpi + camber = included angle, i think) for which have values from previous allignments and they always came out ok.

 

if say i had measurements from a fixed point back right to front left on the chassis and same on the other side, what in your experience could be the max value allowed (mm) before any detrimental effects were caused?

 

thanks again

 

That trim height is fine. On the geo angles it's only the SAI we're interested in.

 

Have you checked the chassis alignment holes?

[mac]

Measuring the body height on each corner is a clue as is if there's a massive difference in the front SAI positions.

 

 

thanks tony

 

body height differs by no more than 3mm when pressures are right.

 

(so kpi + camber = included angle, i think) for which have values from previous allignments and they always came out ok.

 

if say i had measurements from a fixed point back right to front left on the chassis and same on the other side, what in your experience could be the max value allowed (mm) before any detrimental effects were caused?

 

thanks again

 

That trim height is fine. On the geo angles it's only the SAI we're interested in.

 

Have you checked the chassis alignment holes?

 

are those the ones that you use the pins for when positioning the subframe? if so, the pins slot in everywhere fine, a little tight back left but thats it.

[Tony]

I'm not worried about that..... Where did you measure the trim height from/to

[mac]

I'm not worried about that..... Where did you measure the trim height from/to

 

couple of different ways 1 - http://www.familycar.com/alignment.htm#Steering%20Axis%20Inclination%20(SAI) - riding height on that page

 

2- also measured from ground to top or wheel arch trim, more of difference there front to back (was expecting that) but nothing outside 5mm difference from side to side

[Tony]

Can you go again, the link don't work.

[mac]

Can you go again, the link don't work.

 

http://www.familycar.com/alignment.htm#Ste...0Inclination%20

[Tony]

Your best to use this method

[mac]

Your best to use this method

 

 

cheers will do, what sort of range would you allow side to side and front to back?

[mac]

Also something interesting that cropped in during this process, if you were replacing front subframe bolts tony, how would you do it?

 

and if in a certain way, what order would you change them?

 

there was a large debate over this

 

cheers

[Tony]

The only correct way is not to take them all out at once unless you fancy wearing an engine....

[mac]

The only correct way is not to take them all out at once unless you fancy wearing an engine....

 

 

haha even i figured that out. obviously one at a time but the order was subject to debate amongst a couple of guys; clockwise, anticlockwise, diagonal

 

also what type of tolerance would you allow side to side for the trim measurement you outline above.

 

cheers

[Tony]

It depends on the circumstance, is the member has been removed then diagonal, if one side has been dropped to fit wishbone bolts then just gun them up.

 

Time tolerance over the axle is 10mm max.

[mac]

It depends on the circumstance, is the member has been removed then diagonal, if one side has been dropped to fit wishbone bolts then just gun them up.

 

Time tolerance over the axle is 10mm max.

 

 

thanks tony

 

difference is only 2mm side to side on front and 1mm at the rear and measurements are identical front to back on both sides.

 

anyway, one other question, if replacing subframe bolts and you wernt sure that before doing it, the subframe was located exactly perfectly , is it possible to replace the bolts and line the subframe up by eye. my allignment guy doesnt have the pins and says he can do it by eye. Whats your take? do you use the pins?