has anyone changed the mains with the engine still in the truck. If so how hard is it to get the old bearings out. just lookin for some insight before I jump into this.

thanks,
scott

 

Theoretically it is possible but I have never met anyone who has. Pulling the lightweight 351W out would be far easier. Might as well do the rings and head gaskets while your at it.

 

Cold and nasty garage in December in Indinapolis. Worst thing was making the rear main seal fit on a 352. Graphited(?) rope and side seals. If you are on a budget, it is one way to get the job done. Used a roofing nail cut short and kinda bent as the bearing pusher to get the old ones out. Had to turn the engine over by hand in opposite direction, and was so tool hungry - no breaker bar or deep sockets, it was a real pain.
*They* say to loosen the main bearing caps to allow slight clearance for the removal/replacement of the bearings.
It is hard to do the torque without running into exhaust pipes or the frame or steering linkage or stuff they should have put just 1/2" to the left or right.
Can be done, if budget insists. Just oily, messy and not as easy to keep clean. Sure saves on gasket and parts costs.....cuz they are not replaced.
Other times 1)2.3 OHC had what I heard was rod knock.. got slight undersized bearings as a 'justincase'. Was just a loose built engine slightly out of tolerance and lasted at least another 60K miles 2)390 in a '63 T-bird convertible that had sat for 2-3 years and spun the rear main and was drooling oil out the rear seal so fast you had to stop at every exit on the way home to add oil 3) 352 in a '59 T-bird my dad accused me of hot rodding and blowing the head gasket. Was his lack of anti freeze maintainence that caused freeze plug to rust out. We replaced all bearings, and all valves ( why, i don't know), and new rings on a 352 at 60K miles. Sure ran nice when done. Learned a lot, too. Cobblers kids have no shoes, Aircraft Engine engineers cars have no maintenance....
tom

 

I did this in my 460. It sucked.

 

I must be getting old.
Have done it plenty of times.
Drop the pan, remove one main cap at a time.
Get yourself a framing nail, cut the shaft off
with about a 1/4" left under the head. Put it in the
crank oil hole, Bump the engine, the top bearing shell
will roll around and out. Slide the new top shell up the
crank. Replace cap, go to next main cap.




Dre'
1978 F-150, 460ci(750cfm,Edelbrock Performer,Dynomax Ceramic Coated headers,etc.)Auto-C6,373:1 - 9" Posi.

 

Drop the pan, remove one main cap at a time.

You say that like it's as easy as changing plugs in a flathead! :P

Do yourself a colossal favor and follow these 3 simple steps:

1. Borrow a buddy's truck and go rent a cherry picker.

2. Remove the engine from your truck.

3. Replace the bearings.

OR

Do it in the truck, but be sure you've got some good safety goggles and buy plenty of shampoo before you start!

Just my 2 cents!

 

Wow !, you would take an engine out of a truck
just to replace the main bearings?. Anyway,
to each his own.






Dre'
1978 F-150, 460ci(750cfm,Edelbrock Performer,Dynomax Ceramic Coated headers,etc.)Auto-C6,373:1 - 9" Posi.

 

I know on my truck ('89 F250, 4x4, 5.0L, 4 speed), there was no way to remove the oil pan w/o either removing the transmission, or pulling the engine completly.
I don't know if it is possible to remove the pan from a 2 wheel drive truck, or not.

Roger Lane

 

You can do it with the engine in the truck. Some vehicles it's easier than others but most people won't pull and engine just for main bearings. I've never heard of using a framing nail, have you guys been watching the Red Green Show? If you scratch those journals your new bearings won't last very long. Anyways, pickup a couple of bearing rollout pins, there pretty cheap and they work great.

-Jon

 

 

E350 motorhome has 460. Hi Dre. So you're older now. What are the symptoms of a failing main bearing? What I hear and feel is a harmonic vibration at all speeds, not at idle.

 

Welcome to FTE!

Dre has not posted since 8/2002.

Feel free to start a new thread with any questions on any subject. You no doubt have seen the different forums, so try to pick one related to the question.

To answer your question the best I can, with regard to main bearings, wear, which is not failure, results in lower oil pressure as the extra clearance bleeds oil faster than the pump can keep up.

As for failure, it is possible to have the mains fail, and that is usually due to a lack of oil. But, the rods usually fail first when oil dries up. A failed bearing is going to give you a lot of noise and vibration, not just a harmonic vibration. Unless this is enough to blur the mirrors and shake the vehicle. You may have a harmonic balancer that has slipped, causing a slight out-of-balance condition. Or a misfire on a cylinder or two, maybe intermittent.

 

May 86 350 E motorhome is new to me. I will be doing a once-over on the vehicle for deficiencies and maintenance. It all looks pretty good so far. Just that mild harmonic sound migration while driving. Does not when coasting. Cheers G