Newbie goes for the Front end

[azruss]

you dont get stress cracks like that in 200 miles unless you are jumping ditches. That is a pretty important structural piece. Make sure who welds it know what they are doing.

[RRoller123]

Brand new engine cross member for the 78 is 188 bucks, might be best solution? From AR, and others I assume.

[Kta124]

Thanks guys,
I don't' know which direction to go…
Because having it welded by a professional will cost 200$ I guess... same price as a new one. How hard is it to change? Just remove the A-arms, hang the engine somehow and remove it from under? Sounds too easy to be true...

[RRoller123]

Welding it will secure it in whatever bent/distorted situation it presently is in, and there may likely be other defects as yet unnoticed. I would drop in a new one, but I can't say I know how to do this. Others will need to chime in.

Pete

[wizard124]

I think I would have it welded. Changing out the crossmember would end up being more difficult, more involved and time consuming, and more expensive. After all completed you still need an alignment.

Have you taken the car to a local muffler shop for an estimate? Those guys weld and fabricate all day long. Once its welded and reinforced, then check it periodically.

[azruss]

changing it out means removing the suspension on both sides, blocking the engine up and removing from below. I am most concerned about the extent of the stress cracks. Makes me wonder what else is lurking. My other concern is when you weld those up, you create a weak spot next to the weld from all the heat. it can be worked out with peening or heat treating. When you get done, you still have a crossmember with age and rust. If it were my car, i'd be replacing the thing.

[Kta124]

Yes that is what is worrying me a little bit… And I have no welding skills, so I can't tell if I will be played with or not.
Changing it however looks like a long job, but not completely impossible, I have done the front end suspension not too long ago, so I know what to expect and it looks like this will be the longest part of it. What I am worried with is if something is bent, I may not be able to fit a new crossmember in there…
The manual sounds like it is simple but that is if everything goes as planned… Which you already know won't!

And also I don't know if I am making too much out of it but, if it broke and I don't know why I might be fixing it and having it breaking again in a couple of month which would be useless… Is that type of things a regular problem on our cars?

[azruss]

These cars are surprisingly robust. I have owned 124s since 1970 and have put as much as 295k miles on one chassis. The only chronic weak spot on the body (besides rust) is the inner fender support rail that runs above the a-arm in the wheel wells. They want to crack right at the shock. I've never had a crossmember or a-arm stress crack.

[Kta124]

Thanks for your advices!
I am slowly but surely motivating my self (and a few friends) to (help me) change it. My boss, an Afla man (no one is perfect), would let me use his engine hoist, I think this will make it compared to that fiat tool #XXXXXX.99999 to hold the engine during operations. Is there anything that I should think about as I am changing it?
Change the engine mounts, and ?
I will renew the wheel hub spindle nuts as I reused the old ones during the las front end rebuild, and would have preferred ordering new ones…

[BEEK]

place car on jack stands, put floor jack under the front end of the bell housing, you can support the engine and transmission weight right there. no engine hoist needed. very easy way to change a crossmember

[Kta124]

Thanks that sounds like a great tip! It will give me much less trouble!

[Kta124]

OK quick update.
Received the new crossmember last week and started to take everything apart this week end, hopefully I will get there in a week or 2. I will post pics and try keep everyone posted of my discoveries. I already noticed the nuts that are in place are quite a bit rusted so I will give den a shot of WD40 every day from now to the moment I take it down…
I hope it will make it!

[81SPIDERMATT]

change the motor mounts while your there

[Kta124]

Yep, I ordered some new ones as well, even tough the ones on there look ok, it's not worth trying to save them…
So far suspension is gone, i need to unbolt the crossmember, and change it.
I don't feel too confident with letting the motor/transmission hanging on a jack. I don't have a garage and my driveway has a slight slope. I think I will lift it with a jack on the front end of the bell housing, like Beek said, and then secure it with some wood. Just in case something slides/moves a little if the jack slips, I will have some extra safety to keep everything up in the air!

Olivier

[Kta124]

After preparing everything the last week end, I was able to swap the crossmember yesterday with a friend of mine.
I jacked at the front of the bell like Beek suggested:

and added a few pieces of wood for extra safety as my driveway is slightly sloped…

I am using this http://www.mirafiori.com/124susp/ for my torques and general guidance as I did previously when I changed the A arms.
Here is the new close to the older one:

I don't really know if it is the source or the consequence, but I noticed that the upper nut for the horizontal bolt that holds the crossmember to the unibody should be welded to the cross member. I had one that wasn't, and how exceptional, it is on the passenger side, where I have most of the cracks… You can see where the bolt was and that it moved as it scraped the steel around there.

I am happy I took this direction over welding the cracks, because I would never have seen this, and if that was the source of the issue, it would have cracked again… I am glad I choose the hard way, it's supposed to be always rewarding, and this time it was!!

I am supposed to put it all back together this afternoon, we will see if can have it done so quickly… I doubt, but the hardest part is down now.
One quick question though, how hard should I tighten the engine mount bolts? I have never done this before and haven't been able to find any torque specs… even if I will never fit a torque wrench there, I would like to aim for something I could have a sense of…

Thanks all