Bell Housing Dowel-Pins

[searcherrr]

I just put in a new Jasper engine and the warranty says there are no exceptions that the Bell Housing Dowel-Pins must be installed or transmission failure can result. Why would the engine warranty say this? What are the Bell Housing Dowel-Pins and would the engine/tranny work without these installed such that it would be obvious to a good shop that they'd make sure to install these?

Reason I ask is that the Jasper warranty states this and it was in a sealed plastic bag gone "unread" by the shop who did my work. I trust the shop, but they do sometimes miss the lil details though are also very good pointing details out to me as well at times. I know I need to ask the shop if they installed them, but I was wondering if this is one of those kinds of things that they "could've missed" vs "are required because of design and are part of installation" so that when I ask my shop I know if they could be bluffin or not. lol - I trust them, but I guess not 100% cause I wouldn't 100% trust any shop I'm dealing with. This shop though I'd say I trust 99%.

EDIT: Wouldn't these pins already be installed on the transmission before they took out the engine? Can the pins be reused? We're talking about a tranny thats recently rebuilt as well.

[12Ounce]

The dowels are very important for proper alignment of tranny-to-engine. The following isn't the greatest of photos ... it's of 3.8 block sitting, upside down, on tailgate of my Nissan pickup. I've noted the dowels by red arrows:
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. click to enlarge.
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If you look closely, you can see these dowels are actually hollow ... tube like ...two bolts go thru them. (There are actually two more dowels ... smaller diameter and solid. Ford uses these in the engine plant and you don't have to have them ... as they are never used again.) All four dowels, once in place, usually stay there ... it takes a bit of work to remove them. And unless there was some very unusual machine work done on the back of the engine ... they are all probably in place. But Jasper is right, if for some reason the two hollow dowels were not there ... had been removed for some reason... they should be re-added.

[searcherrr]

Originally Posted by 12Ounce

The dowels are very important for proper alignment of tranny-to-engine. The following isn't the greatest of photos ... it's of 3.8 block sitting, upside down, on tailgate of my Nissan pickup. I've noted the dowels by red arrows:
.
. click to enlarge.
.
If you look closely, you can see these dowels are actually hollow ... tube like ...two bolts go thru them. (There are actually two more dowels ... smaller diameter and solid. Ford uses these in the engine plant and you don't have to have them ... as they are never used again.) All four dowels, once in place, usually stay there ... it takes a bit of work to remove them. And unless there was some very unusual machine work done on the back of the engine ... they are all probably in place. But Jasper is right, if for some reason the two hollow dowels were not there ... had been removed for some reason... they should be re-added.

Is there a way to visually verify that the dowel pins are installed once its all back together?

Is there a way to visually verify that the bolts that go in the dowel pins are installed once its all back together?

I would think that you could see the bolt heads on the tranny side right?

If the bolt heads are visible doesn't this mean the dowel pins are present since I would surmise that in order for the bolts to even screw in, the dowel pins must have threads inside them?

Are these bolts that go into the dowel pins the ONLY thing that hold the tranny and engine together?

12Ounce - Did you turn that engine upside down just to show me that? lol - If so MUCHO thanks and either way big thanks!

[12Ounce]

There are 6 bolts that attach the engine to the tranny. The dowels are "clear", not threaded ...not "pins"... the lowest two (...near the crank centerline) bolts pass thru the two dowels. Only by separating the engine from the tranny a wee bit can you verify the dowels are in place.

I wouldn't worry about it ... there is very little chance they are missing.

No, I'm not that considerate ... the photo of the upside down block was already in my records.

[searcherrr]

Originally Posted by 12Ounce

There are 6 bolts that attach the engine to the tranny. The dowels are "clear", not threaded ...not "pins"... the lowest two (...near the crank centerline) bolts pass thru the two dowels. Only by separating the engine from the tranny a wee bit can you verify the dowels are in place.

I wouldn't worry about it ... there is very little chance they are missing.

No, I'm not that considerate ... the photo of the upside down block was already in my records.

I'm just worried that they didn't come with the new engine as I didn't get to scope it out before they put it in and Jasper stated that a new or the old pilot bushing needed to be put on and didn't send one with the engine either. Though the documentation said to "buy a new pilot bushing or use the old one" and when it gets to the part about the dowel pins it does not say whether to buy new ones.... just that the pins MUST be installed or it will void the warranty NO EXCEPTIONS and/or not installing them could cause transmission FAILURE. The part I'm missing here is why could these pins missing cause tranny failure if there are 6 bolts that hold this engine on?

I guess I can just call my shop and ask if they recall putting those on or if they were there already.

Thanks man !

[duke350]

The reason they could cause failure to the tranny is simple. The crank of the engine and the main shaft of the tranny need to be perfectly in line, or there will be stress. The stress will be on both "shafts" and will cause one or the other, or even both to wear unevenly and prematurely. The dowl pins keep the engine and tranny centered on each other. If you just used bolts there would have been some "slop" when you were bolting them up to each other. You would know if you had them or not when you put the tranny on the engine. Did the tranny line itself up, or did you have to hold it up as you put in the bolts? If you had a shop do it, then they assume responsibility, and they most likely had the pin in place anyway.