Frequently Asked Questions

I need advice on what the bearing clearance on my engine should be

Bearing clearance is determined largely by the geometry of the bearing bore and the crankshaft journal. Naturally, the better the geometry, the tighter the clearance you can tolerate. A rule of thumb is a minimum of .0075" to .001" of bearing clearance for everyone inch of shaft diameter, so, for example, a 2.100" Chevy rod bearing journal size would be a minimum clearance of .0016" to .0021". For performance engines, adding an extra .0005" to the minimum is a good place to start. Generally speaking, lower clearances are better because the lower clearance gives a wider, broader oil film contact area, spreading the load over a greater surface area. We know that NASCAR engines run clearances as low as .001" on a 1.850" shaft, but the geometry of parts is very good, there are no sub-zero starts and oil quality tends to be very high. Low viscosity oil works very well with low bearing clearances and just in case you are wondering; ZDDP content really has no effect on bearing/shaft lubrication. To sum it up: For journal bearings, regardless of their material, it is a delicate balance of several variables including the oils high temperature shear viscosity, oil flow through the engine, bearing clearance and the local contact geometries between the bearing shell and crank journal.

I have a big block MOPAR and the thrust bearing will not fit in the block

Well, your problem is an old one, dating back to 1974. In 1974, MOPAR went to a wider diameter thrust surface on the 440. The 59-73 engine was a 3.555 to 3.675" diameter thrust, the 74 and later a 3.870 to 3.930" diameter. Bearings for the older engines will, of course, fit all years where bearings for 74 and later only fit blocks machined for the 3.870" diameter flange.

I need advice on what the bearing clearance on my engine should be

Bearing clearance is determined largely by the geometry of the bearing bore and the crankshaft journal. Naturally, the better the geometry, the tighter the clearance you can tolerate. A rule of thumb is a minimum of .0075" to .001" of bearing clearance for everyone inch of shaft diameter, so, for example, a 2.100" Chevy rod bearing journal size would be a minimum clearance of .0016" to .0021". For performance engines, adding an extra .0005" to the minimum is a good place to start. Generally speaking, lower clearances are better because the lower clearance gives a wider, broader oil film contact area, spreading the load over a greater surface area. We know that NASCAR engines run clearances as low as .001" on a 1.850" shaft, but the geometry of parts is very good, there are no sub-zero starts and oil quality tends to be very high. Low viscosity oil works very well with low bearing clearances and just in case you are wondering; ZDDP content really has no effect on bearing/shaft lubrication. To sum it up: For journal bearings, regardless of their material, it is a delicate balance of several variables including the oils high temperature shear viscosity, oil flow through the engine, bearing clearance and the local contact geometries between the bearing shell and crank journal.

I have a big block MOPAR and the thrust bearing will not fit in the block

Well, your problem is an old one, dating back to 1974. In 1974, MOPAR went to a wider diameter thrust surface on the 440. The 59-73 engine was a 3.555 to 3.675" diameter thrust, the 74 and later a 3.870 to 3.930" diameter. Bearings for the older engines will, of course, fit all years where bearings for 74 and later only fit blocks machined for the 3.870" diameter flange.

I have used bearings from my engine - I don't know the size and they're not stamped with a size

We are sorry! We know you desire an easy answer to the size of your bearing but in the past, size was marked with an ink stamp on the back of the bearing and in 99% of the cases, it has been washed off by the time you have the bearings out. Now days, we mark it on the back using a steel stamp so it remains forever. The only two sure ways to know the bearings size is by measuring the crankshaft diameter and comparing it to standard or, using a ball micrometer, accurately and carefully measure the wall thickness of the bearing shell 90 degrees from the parting line.

I have a rubber bushing that says Clevite on it

The rubber bushing business: " Clevite Elastomers" was sold a number of years ago to TENNECO.You can find them on the web.

I can’t find a coated Clevite bearing for my engine

We often get customer inquiries for coated bearings that we do not produce. We deal with three excellent and well-known coaters in the USA and any of the three can meet your needs for a coated Clevite bearing. They are: CALICO Coatings in Denver, NC, HM Elliott in Mooresville, NC and POLYDYN in Houston, TX. They all can be accessed via a web search. Tell them they were recommended by MAHLE Aftermarket Inc.

Can you make me a set of bearings

We often get request for custom bearings and unfortunately it is not as easy and simple a matter as folks think. Engineering and tooling cost (if tooling for a particular size does not exist) plus lead times of 20-40 weeks and a minimum order of 1000 pieces per size make it a pretty daunting task for the average person. Most custom bearing orders come from customers with sizable needs or large niche markets available to sell the product. I would encourage you to check with the other bearing suppliers in the chance they might have coverage. If you want to pursue a special order, please contact us.

I live outside of North America and want to buy just a set of bearings

Most of our USA retail customers accept credit card orders for parts to be shipped overseas. These would include; CV Products, JEGS, Motorstate Distributing, Nichols Performance and Summit Racing. Feel free to contact them directly to purchase our parts. Thank you for choosing MAHLE parts!

Your H series bearings look ugly. I think they are defective

This is a common question for first time users of H series Clevite bearings. Stock bearings have a coating applied called "flash tin plate" that is a couple of millionths thick. It gives the bearings the pretty silver look and protects them as they sit on the shelf waiting to be sold. Most racers used an abrasive to remove the tin plate because it is not good for racing and performance. Some years ago we decided if racers wanted the tin plate removed, we'd just leave it off-hence the funny look to the H series bearings. Use them"as is" and you'll be just fine! Thanks for choosing Clevite brand bearings.

I can’t find an H series rod bearing, only HN

About 3/07 we made a running change on H series rod shells. We narrowed the bearing shell by the same amount that was formerly relieved by the large chamfer and we changed the part number to a HN suffix. The net effect to the engine is the same, the bearing area the same and the crush on the shells the same. We'd been doing the narrowing to V series race bearings for several years and wanted to standardize the manufacturing processes across the families of bearings. As long as you don't mix the old style and the new in the same engine (slight difference in weight could affect balance in a racing engine), you'll be just fine! Thanks for buying Clevite.

I have this part and it says MAHLE on it and I can’t find it in your catalog

We are sorry. Often customers have a bearing or bushing that says Clevite on the back or a piston marked MAHLE. In the majority of these cases, the part was manufactured only for the engine/equipment manufacturer and no aftermarket/service parts exist unless from that equipment manufacturer. The other possibility is that the engine you have is old enough that we have discontinued offering the parts, hence you cannot find a listing for it. In that case

Some good sources of old-obsolete parts are:

Olsons Gaskets@ 360-871-1207 or olsonsgaskets.com

Packard Industries @866-902-0662

Mills Motor Parts @800-624-7999

EGGE Machine CO.@egge.com or 800-866-3443,AG kits.com @ 1-800-437-3609

The oil squirt hole is missing from the Clevite rod bearings I bought from you

Yours is a very common question. In the old days, they (Chrysler, GM and Ford) squirted oil through that hole to the cylinderwall to oil the piston. Now days and for quite some time now they do not do that. Better oil, better pistons, smarter engineers, have made it obsolete. Use the bearings as is and you'll be just fine! Or, if you feel absolutely compelled to, file the hole being careful not todamage the bearing shell in the process. In either case, thank you for buying our Clevite brand bearings!

I need a Clevite bushing

You best chance to get the bushing in question is to contact our distributor for bushings:

Stellar Group SRKG Acquisition LLC

4935 Panther Parkway

Seville, OH 44273

att: Andy Stuthard

Phone: (330) 769-8484 x17

Fax: (330) 769-8483

My bearings I bought from Clevite are missing the locating lugs/tangs

More and more manufactures are eliminating the bearing tang and corresponding notch in the rod/block/cap. It's a means of saving money. When the manufacturer makes the change during the model run of an engine, we change to the bearing without the locating lug. As long as the bearing is lined up correctly, there's nothing to worry about as something called bearing crush that we build into the bearing keeps the bearing from moving once the rod or main bearing is assembled and torqued.

I live in North America and want to buy direct from MAHLE Aftermarket Inc

To buy direct from MAHLE Aftermarket Inc, you must first become a customer. To become a customer, you need to have an active business that can sustain an annual purchase volume of $50,000, an initial order of $10-15,000 and you ll need to meet other criteria that will be discussed when you are contacted by our sales rep. If you feel you'll be able to meet the financial criteria, please respond back via the CRM tool and we'll have our representative contact you. If not, this link will take you to a look-up tool to find an existing distributor of our parts

I have a problem with a MAHLE/Clevite branded part that I purchased

We are sorry you experienced a problem! There is a procedure in place that needs to be followed to make a claim. It is simple, but it is the way all claims must be submitted.

1) Please go back to the store where you purchased the part(s), taking the used parts as well as the any paperwork from the shop or dealer where you had your vehicle fixed.

2) The dealer will fill out claim paperwork that gets sent, along with the used parts, to MAHLE's Engineering Services department.

3) MAHLE's Engineering team will examine the parts for proper size and construction as well as correct installation and also confirm that dealer sold you the correct parts for your application.

4) This process, once we have the claim in hand, can take several weeks to complete.

5) When we (MAHLE) have completed the evaluation, the information will be sent back to the dealer /store where you purchased the parts and they will contact you at that point.

I live outside North America and desire to buy MAHLE Aftermarket product

We have agents and direct MAHLE sales people covering over 90 different countries. All inquiries should be directed to those individuals. You can find the person for your country by going here:

In the event you don't find a listing for the country where you live, please use CRM inquiry and we'll direct your inquiry to the correct person.