Front Motor Mount: Tight or Loose?

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Model T Ford Forum: Forum 2005: Front Motor Mount: Tight or Loose?
Top of pagePrevious messageNext messageBottom of page Link to this message  By Jeff rey L. Vietzke on Thursday, February 14, 2008 - 12:02 am:

Hello. The thread on the wishbone socket springs got me thinking. (Yes, I run my springs loose back there!): How tight is the front engine mount supposed to be? I have mine TIGHT and safety wired, but after giving it some thought, shouldn't it be just a tad loose, and greased to boot? I couldn't find any specific info in the Green Book, but DID note that it was refered to there as a "bearing". That being said, is it to be snug, or TIGHT??? Thanks.......
Jeff


Top of pagePrevious messageNext messageBottom of page Link to this message  By Val Soupios on Thursday, February 14, 2008 - 12:17 am:

It should be well greased and loose enough to allow the nose of the pan to twist when the chassis flexes but not so loose that it has any up and down movement. I usually put one wrap of electrical tape around the part of the crankcase that sits in the motor mount before I grease it up and lay the motor into the chassis.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ray Elkins on Thursday, February 14, 2008 - 05:38 am:

Yep, what Val said. If it can't rotate under pressure, the nose of the pan can be twisted and break the solder, or the rear mount ears flexed to the point the solder breaks. Either will cause a leak in the best scenario.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Michael Bunner on Thursday, February 14, 2008 - 10:57 am:

isn't that why the ears don't go all the way down on the nose, so it has room to flex? I was wondering why they seem to float about 1/4'' off the surface...


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ray Elkins on Friday, February 15, 2008 - 06:38 am:

I'm lost Michael. What ears? Helpr me understand :-)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jim Patrick - (2) '26's - Bartow, FL on Friday, February 15, 2008 - 08:53 am:

Brilliant topic Jeffrey. After 38 years in Model T's, I'm embarrassed to say I never really considered that the nose pan securement assembly at the front crossmember is really a bearing that should be lubricated and allowed to move. When I first bought my 1926 coupe in original condition, in 1970, the nose pan bearing and nose pan securement assembly cap and mating surfaces were totally rusted, so it was never lubricated or treated as a bearing, as far as I could tell, but that is not to say that it shouldn't have been. While I assume it won't move enough to do much damage to the pan, it is an obvoius flexpoint, incorporated into the design for a reason, so from here on out it will be greased along with the other lubrication points, so it can move if it needs to. I assume it will move, even if tightened down fully with the bolts and locknuts provided. Thank you. Jim


Top of pagePrevious messageNext messageBottom of page Link to this message  By Michael Bunner on Friday, February 15, 2008 - 10:06 am:

hmm... the nose of the pan has a cap on it that has two ears. So, I'm trying to figure out why mine aren't flush with the front crossmember that the nose of the pan sits in. If I remember correctly, it had a couple of washers in there as spacers between the ears and the front crossmember bracket.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kenneth H. Todd on Friday, February 15, 2008 - 10:55 am:

Michael, it shouldn't sit on the crossmember, it should sit on the front spring clip.
Where the crancase sits, both the clip and the cap should be almost identical in shape, that is, half round.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Michael Bunner on Friday, February 15, 2008 - 08:00 pm:

kenneth,
You called it a clip, I called it a crossmember bracket. But, the question remains, how much distance between the cap and the clip/bracket? Mine do not touch.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mack Jeffrey Cole on Friday, February 15, 2008 - 08:33 pm:

Michael,a photo or 2 of your situation may help us help you.

Back to the question.
The motor mount that sits down over the crossmember that also retains the front spring,I tighten it down good.But I also tighten the bolts that hold the little cap on top of the starter bushing holder part of the pan.I never thought of it as a pivot point but by gosh it makes perfect sense that it would act as 1.

But my question has allways been,and I ask a few members of the club about this recently.
I have repaired a couple earlyer chassises that had cracked crossmembers in the front.All were obviously equiped with the 2 ubolt motor mount.I am wondering if those are tightened alot and the car driven over rough ground,that it could stress the crossmember in the center,it's weakest point because of the spring bolt hole and cause the break?
All the later chassises I come accross that were equiped with the single clamp type arent cracked in this way. Could that be the reason for the change in parts design?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ray Elkins on Friday, February 15, 2008 - 08:34 pm:

They should touch, Michael. Either shim it or find out what is holding the pan up. Something is definitely wrong there.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ray Elkins on Friday, February 15, 2008 - 09:00 pm:

The unit that you are talking about, Mack, was introduced in '21. Before that the two u-bolts and separate engine support were used. From an engineering standpoint, the single spring clamp is definitely easier on the crossmemeber, and I can imagine that many of the early ones would be cracked since the distance between the u-bolts would cause constant pressure on the center of the crossmember. Even the radiator vendors stress that most frames will be spread and the mounting bolts will be farther apart than they were originally. The '21 and later design removes the constant pressure pulling the ends of the crossmember down.

From a manufacturing standpoint, the new design would have been much more economical in both parts price and labor savings. As you know by dealing with both styles, the new style is much simpler to assemble than the old-style. The old style consists of 2 u-bolts, two straps, four nuts, engine support bottom and top. The new style is engine support and cap, 2 nuts, and spring clip bar. It's not hard to see the benefits of the new design.

Michael, what style do you have? What year is yours. While we're at it, can you post a picture of your Smith Formatruck? Is it the chain-driven one?

Ray


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bob Frink on Friday, February 15, 2008 - 09:57 pm:

If I'm not mistaken, all the caps are not the same size. You may have a mismatch.
Bob


Top of pagePrevious messageNext messageBottom of page Link to this message  By Michael Bunner on Friday, February 15, 2008 - 11:20 pm:

front bracketfront bracket 2

Ray, I wish it more than just a pile of parts. I'll post more pics when it's a rolling chassis. Hopefully in the next two weeks. I have everything I need, just having troubles getting it all to go together without mishaps.

I made a BIG MISTAKE today. I didn't listen to my own voice of reason. If it ain't broke, don't fix it... I decided to replace one of the spindle arm bushings... I received many with my new bolts; ouch. two hours of cussing.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Michael Bunner on Friday, February 15, 2008 - 11:22 pm:

oh, and what size are those two bolts that go into the cap holes? I have a big box of parts, but no new bolts for the front end... looks like Ace Hardware owns my business for the next 6 months. Seems like they have all of those little items that the big guys lack.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ken Kopsky on Friday, February 15, 2008 - 11:53 pm:

This is what happends when the snout can't move inside the clamp. It's called a bearing for a reason.

Left Side

Snout-Left

Right Side

Snout-Right


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ken Kopsky on Saturday, February 16, 2008 - 12:06 am:

Forgot to mention:
I guess you know what would happen if the crack is allowed to propagate all the way across.

Michael - I don't recall the size. I think they'er 3/8 or 7/16 course thread. If you want to be "correct", the bolts have high rounded heads.


Top of pagePrevious messageNext messageBottom of page Link to this message  By jack daron-Indy. on Saturday, February 16, 2008 - 12:32 am:

Ken I think 7/16 NC and at least some of the earlier ones were flat hex headed and some even drilled for safty wire.Round heads in 26-27.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ken Kopsky on Saturday, February 16, 2008 - 01:12 am:

Yeah, you're probably right about that Jack. I'm recalling what was on my late 25, and the current 26 in the shop. When are those CDs going on sale? ;)


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