Broken Heat Exchanger bracket on 35-3

[Greg K]

My boat partner and I have a 83' 35-3 with a Universal M30 engine. While doing a routine check on the HX zinc, we noticed a deep dent on the HX. The dent was about 1/8" deep and touching the mounting bolt of the HX bracket. It must have been caused by the bolt digging into the HX with all the engine vibration - installer's error (guilty as charged). Good thing the dent did not go through the HX. We removed the HX and patched it up with JB MarineWeld epoxy from Home Depot. That seemed to do the trick to repair the HX dent.

After removing the HX, we found another cause of the problem. Our HX bracket was broken and not offering stable support to the HX (see photos), causing more vibration. I've been looking all around the web to find a replacement bracket, but no body seems to sell that part. If anyone knows where I can buy this part from or knows of a workaround for this problem, please let me know.

Another challenge in this repair job is the bracket mounting bolts. They are super seized and would not budge. I guess I'll just have to do that dance (heat, lube, force, repeat) with them until they come off.

 

[Loren Beach]

Hmmm. Bracket looks very similar to the one on our former M25XP. Stamped steel, IIRC.
Strictly mentioned in the "FWIW" vein, I recall someone on this site discussing how they moved their HE off of their Universal diesel, to one wall of the engine compartment. This allowed useable access to the top of the transmission for checking lube level. Hoses had to be reconfigured a bit.

I experienced one unexpected coolant leak when the short hose to the HE came loose; it was a very tight fit to get it back into place on our model.

I always had to pull both attachment bolts and move the HE a bit, just to access the dip stick. Interestingly enough, our mounting bolts were never hard to remove. You sure have my sympathies.
Good Luck!

 

[Prairie Schooner]

My boat partner and I have a 83' 35-3 with a Universal M30 engine. While doing a routine check on the HX zinc, we noticed a deep dent on the HX. The dent was about 1/8" deep and touching the mounting bolt of the HX bracket. It must have been caused by the bolt digging into the HX with all the engine vibration - installer's error (guilty as charged). Good thing the dent did not go through the HX. We removed the HX and patched it up with JB MarineWeld epoxy from Home Depot. That seemed to do the trick to repair the HX dent.

After removing the HX, we found another cause of the problem. Our HX bracket was broken and not offering stable support to the HX (see photos), causing more vibration. I've been looking all around the web to find a replacement bracket, but no body seems to sell that part. If anyone knows where I can buy this part from or knows of a workaround for this problem, please let me know.

Another challenge in this repair job is the bracket mounting bolts. They are super seized and would not budge. I guess I'll just have to do that dance (heat, lube, force, repeat) with them until they come off.

Hi Greg,
Our bell housing is aluminum. If yours is, be careful with extraction.
We repositioned our HX. Our '86 M25 has a different style holder, otherwise you could have our old bracket. Small help, right. I'll be posting those pictures in the Coolant Conundrum thread in the next week or two. If you have urgent need of a ref photo, lmk. For our configuration a wall mount didn't work.
Jeff

 

[Christian Williams]

It is possible to step on that bracket pretty hard in the darkness, and maybe somebody did that over the years.

Looks like the frozen nuts are candidates for an impact wrench and lots of PB Blaster. They ought to come off, and then the plate can be repaired by a welder.

You can move the heat exchanger off the engine just by lengthening the hoses, if there is a better place to mount it.

 

[Greg K]

It is possible to step on that bracket pretty hard in the darkness, and maybe somebody did that over the years.

Looks like the frozen nuts are candidates for an impact wrench and lots of PB Blaster. They ought to come off, and then the plate can be repaired by a welder.

You can move the heat exchanger off the engine just by lengthening the hoses, if there is a better place to mount it.

Good suggestions. Will see what works and keep you all posted. Thanks everyone for all the responses.

 

[Prairie Schooner]

@Greg K
Hi Greg,
Post # 179 shows how I ended up mounting the HX.

Jeff

(Have you ever noticed that people say, "A penny for your thoughts." but folks usually offer their "two cents worth"?)

 

[Greg K]

Hi Jeff,
What a clever way to mount the HX! Thanks for sharing the post. But we ended up getting a local welder to repair both the bracket and the HX. He also added a back plate to reinforce the bracket. $70 for the job. The place is called Elco Wedling in Venice, CA, if anyone is interested.

-Greg

 

[Prairie Schooner]

Hi Jeff,
What a clever way to mount the HX! Thanks for sharing the post. But we ended up getting a local welder to repair both the bracket and the HX. He also added a back plate to reinforce the bracket. $70 for the job. The place is called Elco Wedling in Venice, CA, if anyone is interested.

-Greg

That's a great cut-to-chase solution, Greg. I over think things. But after almost seventy years I try to pass it off as a feature, not a bug. Happy motoring!