Deeper pilot bushing

[cobragene]

I have a 428 and TL with small and short input shaft I need to use a .16” spacer between trans and 5.5” Lakewood for HTOB clearance so I had to get a deeper pilot bushing, I have read that if the bushing is hanging out of the crank it can work loose so I thought I would red loctite it before driving it in. I received the bushing and it has a .90” deep steel outer band and a .75” deep bronze inner bushing I will be installing it so there is .25” of the bronze bushing hanging out of crank, the steel bushing OD is just a hair larger the the all bronze bushing so it will be tight. I am worried that the steel on steel crank may seize over time now I don’t know if I should use anti seize, loctite or nothing? Any input

[eschaider]

Rather than cobble together a compromise solution, why not get the measurements you require (sounds like you already have) and then head out to your local job shop machine shop. Have him make a single piece silicon bronze bushing for you that fits the crank both in its diameter and also depth but also gives you the additional length you are looking for to support the input shaft.

You will be modestly more expensive than the store bought and user modified bearing solution and much more functional and durable..

[cobragene]

All of the dimensions are good, I am just not sure of the steel on steel, is that why you have those recommendations? Thank you

[eschaider]

Steel on steel is a no-no. It will seize, minimally damaging your input shaft and potentially damaging your crank. All the older OEM pieces were made of oilite silicon bronze, because it is such a good bearing material for a hardened steel input shaft snout.

[cobragene]

The inner portion of the bushing is bronze, you don’t think anti seizure on the steel to steel will do the trick or would the bushing be able to walk out of the crank?

[eschaider]

The OD of the bushing is supposed to be a press fit into the back of the crank. It is not supposed to spin in the crank. Because the entire pilot bearing is a press fit, it will rotate with the crank.

The input shaft will only spin inside the pilot bearing during gear changes. Other than those moments when the clutch is disengaged, and the synchros cause the input shaft to rotate at a different speed during a gear change, the input shaft will always rotate at the same speed as the crank.

[jknich]

What Ed said!

[cobragene]

http://www.clubcobra.com/forums/atta...1&d=1674356126
I hope these pictures appear, I bought this bushing from Modern drive line, it does have an interference fit in the crank and the input shaft turns freely inside of the bronze potion, and it just occurred to me that pilot bearings are steel on steel, but since how the bushing is hanging out of the crank I don’t want it to work it’s way out of crank so red loctite would prevent that also prevent seizing?
Thanks for taking your time.

[eschaider]

The bearing OD should be a press fit. I have no doubt Modern built it that way. Once you presss it into the crank it is not going anywhere — no Locktite® required. The bronze insert will provide the support the input shaft needs w/o the danger of a steel to steel seizure, which is the proper way to design the bearing.

The bearing looks to be everything you need. Just be sure it is a press fit. Before installing it clean the bearing register in the back of the crank, clean the bearing OD, apply a light coat of oil and press the assembly together. You will be good to go.

[cobragene]

Don’t pound it in like a regular bushing? Engine is in car so if it needs pressing in how do you do that?

[incoming]

Set the bushing on a 100w light bulb for a couple of hours. Wearing heavy gloves, pick up the bushing and slide it on the shaft.

[DanEC]

Actually he needs to put the bushing in the deep freeze overnight and put a heat gun on a lower heat setting of a small space heater on the crank end - don’t want to get it too warm. With some luck the bushing will slide into the crank recess or at least seat with a few relative easy taps with a hammer on a piece of wood. But is the brass portion of the bushing loose in the steel surround? It needs to be fixed so it doesn’t rotate with the input shaft. It could be that as the bushing is seated in the crank it will shrink and tighten slightly on the brass locking it in place. Just have to try it and see. Hopefully the steel bushing OD is not more than a couple thousands of an inch interference fit.

[cobragene]

DanEC the bronze bushing is pressed tight into the steel outer band no movement there, Modern Drive Line states the OD being 1.85 I have two calipers and both read it is 1.87 OD. An ordinary new bronze bushing I have measures 1.85. My flywheel is mounted and my caliper won’t reach into the crank recess to get that measurement. .02” plus it being steel sounds like it may need to be pressed on?

[sunman]

Use a bushing install tool and gently tap bushing in.

1.852 is what DanEC said. Two (2) thousands, .002 over maybe with hot crank n frozen bushing. Probably needs to be 1.850 like your bronze bushing.

1.870 is to big if you have a 1.850 crank.

[eschaider]

You can also make your own tool to do the job.

Get a piece of 1 inch square steel bar stock (or a bit larger if 1" is not available) that is a little longer than the OD of the crank flange. If your crank uses ½" hardware drill two 9/16" holes at opposite ends of the steel bar that line up with the two flywheel attaching bolt holes.

Get two set screws from McMaster, or wherever you buy you tools, that will screw into the crank bolt holes and allow you to slip the pilot bearing in place and then 1 inch square steel bar over it. Put on hardened steel washers (McMaster) and a grade 8 nut (McMaster) on each set screw.

True up the bar stock so it is parallel to the back of the crank and flat against the throwout bearing and begin tightening the nuts one nut at a time, one quarter turn at a time untill the pilot bearing is pressed into the crank and seated at the bottom of its register in the back of the crank.

Presto, Viola! You are done. Don't forget to lube the crank register and the pilot bearing OD. As a general rule of thumb a 0.001" press fit is adequate, a 0.0015" press fit is tight. A 0.002" press fit wil require chilling the pilot bearing 10˚C to 20˚C below zero and heating the back of the crank to expand the register.

The heating and cooling approach to installation is not recommended with the crank in the block. The heat will damage the oil seal and you will have a leakage problem.

If the bearing is in fact 0.002" oversize, the right fix is to have a local machine shop take 0.001" off the OD. If it is not already chamfered, chamfer the leading edge of the pilot bearing to make centering and installation easier,and you will be good to go.

[DanEC]

That’s why I suggested a heat gun on low or space heater on the crank end. A little heat can help, especially in winter time. But too much heat could risk damage to the rear seal and any RTV in there. You should be safe to get it up to 100 - 120 degrees. The engine runs much warmer than that. If you have a cold garage and the crank is about 50 or 60 degrees it’s just making things tougher for you. I like Eschraider’s comment on trying to get down to .001 interference fit. I’ve struggled with too many transmission and differential bearings with .002” or more interference fit. I’ll hone then out to get that down by half.

[sunman]

1.870 is 2 hundreds over not 2 thousands.

It is to big for a 1.850 hole and will never fit.

The bushing should tap in with no problem you don’t need no press.

Modern Drive Line said it is 1.850 if it’s not send it back and get the correct bushing.

[Alan P]

Originally Posted by cobragene

I have a 428 and TL with small and short input shaft I need to use a .16” spacer between trans and 5.5” Lakewood for HTOB clearance so I had to get a deeper pilot bushing, I have read that if the bushing is hanging out of the crank it can work loose so I thought I would red loctite it before driving it in. I received the bushing and it has a .90” deep steel outer band and a .75” deep bronze inner bushing I will be installing it so there is .25” of the bronze bushing hanging out of crank, the steel bushing OD is just a hair larger the the all bronze bushing so it will be tight. I am worried that the steel on steel crank may seize over time now I don’t know if I should use anti seize, loctite or nothing? Any input

Sorry to bother you. I am new to this...how do I Post a Thread. Site says there is a thread button but I cannot find or activate it.

Thx in advance, Alan

[cobragene]

Alan ,you have to be signed in, then choose a topic under forum header like FE engines, then you will get a post new thread option. Good luck

[cobragene]

Sunman I am dealing with Modern drive now about the oversize