Beautiful day, but.... what the?

[Jtown]

Okay, bit the bullet and ordered factory upper and lower rear control arms. Everything looks good but what do you guys think about this line that looks like a crack in the casting?

It's not an excess slag line, it looks like a crack running pretty deep from what I can tell. I can send it back but they don't have another one. I'd have to start looking elsewhere. Interesting, they all are made in the UK. Is there lots of stress on that cross bracing? I'd assume so. I asked a suspension shop but they were indecisive.

Funny, I'd bet if this was on the assembly line, it would go in a car and no one would ever know.

 

[AmsterDutch]

Okay, bit the bullet and ordered factory upper and lower rear control arms. Everything looks good but what do you guys think about this line that looks like a crack in the casting?

It's not an excess slag line, it looks like a crack running pretty deep from what I can tell. I can send it back but they don't have another one. I'd have to start looking elsewhere. Interesting, they all are made in the UK. Is there lots of stress on that cross bracing? I'd assume so. I asked a suspension shop but they were indecisive.

Funny, I'd bet if this was on the assembly line, it would go in a car and no one would ever know.

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Which part is that crack on? Left? Right? It looks like the lower control arm right? If you return it they have some ACDelco Brand Rear Lower Control Arms on Amazon

• ACDelco 45D10250 Professional Rear Driver Side Lower Suspension Control Arm
• Only 1 left in stock (more on the way).
• Free Shipping for Prime Members

$158.17

• ACDelco 45D10249 Professional Rear Passenger Side Lower Suspension Control Arm
• Used, Very Good
• Only 1 left in stock - order soon.
• Free Shipping for Prime Members

$123.55

 

[AmsterDutch]

That right Rear Lower control arm was $139 but just dropped to $123 yesterday it's a returned used part but don't let that scare you ...most parts that are returned I found haven't ever been installed and are still in the original package

 

[Jtown]

Sorry, it's the right rear upper. 6W4Z-5500-AA. Got it for $92 but I guess that don't mean squat if it's bad. Has anyone heard of these parts being bad?

 

[AmsterDutch]

Sorry, it's the right rear upper. 6W4Z-5500-AA. Got it for $92 but I guess that don't mean squat if it's bad. Has anyone heard of these parts being bad?

Never bought any rear suspension parts myself but I'm going ACDELCO when I have to finally pull the trigger...which will be soon for both my 06' and 02'

 

[capt fast]

surface flash caused by cold mold and slow pour. fear not. mine are like that and in service. use or not is still in your court. the lower casting gets the most stress from loading and road hazards, .
If it was a benz or bmw part, it would probably be forged not cast. and pricy. cast is cheap and it shows. I always felt the lowers which are exposed to road damages should be steel alloy instead of cast aluminum. but, that is just me.
I went out and looked at my 98 mark8 and jag lowers, they look like investment castings and very smooth/clean. the uppers on the jag look like this.

 

[Jtown]

surface flash caused by cold mold and slow pour. fear not. mine are like that and in service. use or not is still in your court. the lower casting gets the most stress from loading and road hazards, .
If it was a benz or bmw part, it would probably be forged not cast. and pricy. cast is cheap and it shows. I always felt the lowers which are exposed to road damages should be steel alloy instead of cast aluminum. but, that is just me.
I went out and looked at my 98 mark8 and jag lowers, they look like investment castings and very smooth/clean. the uppers on the jag look like this.

Thanks Capt. I swear it's a crack but I don't have the equipment to inspect it or confirm. Like I said, if it was on the car, I'd never know (probably). The opposite left side rear upper is smooth with no flaws. Definitely want to hear from the experts here before I decide.

This car is going to be available for guests that visit so I want it to be dependable of course. Have gone through the suspension, brakes, all fluids and filters, coils, plugs, gaskets (valve cover), tires, couple interior issues...

 

[RodLS]

I just redid my rear suspension and didn't notice anything like that. The casting was a bit rough in a few areas though. I should take a closer look when I get home.

 

[Jtown]

Look at all that beautiful FoMoCo stuff!

 

[RodLS]

The old parts are not so beautiful. 230k on them and I was getting a clunk from one side.

 

[Jtown]

Ay Caramba! So my stuff has 53K miles and salt free. Bushings boots are definitely torn up on mine but maybe I should consider running them longer. No way, I can't take it! They are going on Monday.

I was going to do it myself but I have a speed shop that will do it for $110 per side. That sounds decent (I think). My take-offs are rust free. Maybe someone wants them?

 

[AmsterDutch]

Ay Caramba! So my stuff has 53K miles and salt free. Bushings boots are definitely torn up on mine but maybe I should consider running them longer. No way, I can't take it! They are going on Monday.

I was going to do it myself but I have a speed shop that will do it for $110 per side. That sounds decent (I think). My take-offs are rust free. Maybe someone wants them?

Would like to see what they look like after your shop takes them off...if they're still decent I would be interested ...since all these parts are disappearing

 

[04_Sport_LS]

Ay Caramba! So my stuff has 53K miles and salt free. Bushings boots are definitely torn up on mine but maybe I should consider running them longer. No way, I can't take it! They are going on Monday.

Considering the low milage...

As long as the rubber bushings aren't split or torn from age... the split boots could be replaced separately.

There is a thread over on one of the Jaguar forums, (somewhere), where a member was able to source those boots.

As far as the ugly upper arm...

I suspect that the mould used to cast that arm was near the end of it's life and no longer smooth... and part of it stuck to the arm when removed. Thus the "layered", (not cracked), look of the arm.

If the "crack" doesn't appear to go all the way through to the other side... then you are probably ok... but as said... it is up to your discretion. I'm only looking at pics and don't have the part in hand.

 

[04_Sport_LS]

As an afterthought...

You could clean up the "cracked" area by filing it smooth... then scrubbing it with a stainless steel toothbrush in the direction of the crack.

Then testing the area with something like this:

https://www.amazon.com/Dye-Penetran...words=dye+penetrant+kit&qid=1570384678&sr=8-4

Doing this however, may negate the option of returning the part for a replacement... and using the dye-pen without smoothing the area may result in a "false positive".

 

[04_Sport_LS]

I would be interested ...since all these parts are disappearing

Most of these parts don't have all of the replacement bushings available... and NONE of the upper arms have the ball joint available separate. They are considered a "wear item" with a new arm as the ONLY option.

 

[capt fast]

Thanks Capt. I swear it's a crack but I don't have the equipment to inspect it or confirm. Like I said, if it was on the car, I'd never know (probably). The opposite left side rear upper is smooth with no flaws. Definitely want to hear from the experts here before I decide.

This car is going to be available for guests that visit so I want it to be dependable of course. Have gone through the suspension, brakes, all fluids and filters, coils, plugs, gaskets (valve cover), tires, couple interior issues...

 

[capt fast]

you could consider giving the cast part the hammer fail test with the largest rubber mallet you can find. smack it opposite the suspected crack with the ends supported. don't act like Thor trying to open a fissure in a cliff face, be moderate. If the part deforms, it is done. castings don't like bending at all. if it doesn't open the crack or deform the part, it may be good. if the suspected crack opens up it will take a set and not close up. then you know its a crack. cracked castings behave like that. if the crack opens up, your not out anything you weren't before you smacked it. if there is no crack, the rubber mallet is only applying a short duration pressure and not an sharp impact like a steel hammer does-no harm no foul. you could find a shop with a dye penetrant test kit and pay them to test it, but the roughness of the casting make that test problematic. dye penetrant testing works much better on forgings.

 

[Jtown]

Thanks again Capt. I agree with your method but here's what I did: I went ahead and installed it because I'm moving and won't find a dependable shop like I have here now. I figure if it fails, I'll have to replace it and would then do it myself. The cost is a wash between buying a new arm and offsetting it with my labor to install.

I will post a pic of the original rear arms vs. the newer Jag parts. There cross support is solid on the FoMoCo 2003 part and doesn't have the hole in the design like the Jags stuff.

I had an alignment done but didn't supply the caster adjustment hardware so they did the best they could. My "toe in" was way out after I installed tie rod ends myself.