We overhauled this 1958 Ferrari 250 engine 12 years ago and it has run a bunch of tours with Rich and Jean Taylor at Vintage Rallies as well as the Ferrari Challenge Rally a few years ago. When we overhauled the engine we converted it to coil valve springs from the hair pin style – making a strong engine even stronger. It must have higher lift cams and a bump in compression because it made some killer power on the dyno years ago. I promise to put it on the chassis dynomometer when we fix it.

What failed is what typically fails on 308′s and Berlinetta Boxers – the small caged ball bearings in the timing chest. The inner generator drive bearing came undone, and the cage got into the main bearing scouring the cap and the bearing. We are having the journal built up to standard and are going to check the line bore to make sure the cap is still square to the crank pins.

While the block is set up on the line hone machine, the rear cap will be cut to accept a 100mm oil seal. Normally these engines rely on the “slinger” arrangement. With the rest of the engine in such good condition, we will clean and inspect everything but probably not have to replace too many expensive parts such pistons or perform a valve job.

Bearing failure

Damaged main bearing

Bearings messed up

We rarely have to repair rear axles and usually just clean and inspect the bearings and install new oil seals. Be it a Jaguar, Chevrolet or Alfa Romeo, it is rare that we see a ring and pinion that is damaged or bearings that are worn out. I hate to disturb the factory relationship between the ring and pinion gears so if the bearings check out ok, I keep the thing together.

Additionally, most car companies have figured out how to make the final drive robust and problem free because they are aware of the forces involved with the ring and pinion bevel gears – except for Ferrari. They used a deep groove ball bearing and sliding inner race roller bearing that cannot handle the axial loads on the pinion shaft. Other companies used tapered roller bearings that can handle a tremendous amount of this fore-and-aft thrust while spinning with ease but the Ferrari style comes apart and destroys the gears.

My solution is to replace the sliding inner race roller bearing and the deep groove ball bearing with a pair of tapered roller bearings. This photo is a 250 GT Lusso center section with the “chicklet” style limited slip differential. On some axles I’ve install tapered roller bearings to support the differential but on the later axles there isn’t much room to install this type of bearing and I have found the original ball bearing set up to be adequate. I have done this conversion to many cars that have gone many thousands of miles with no issues.

Final drive Ferrari

GT Ferrari 250 Axle Center section

After overhauling dozens and dozens of Ferrari transmissions I have a good idea on what to expect when the case is opened up and shafts are broken down. Whether it’s a 250 GTE 4 speed, a 246 GT Dino trans-axle or a 330 GTC/Daytona style 5 speed trans-axle,  synchronisers on Ferrari’s do not last many miles however, the rest of the components are over built and hold up well.. The bearings and gears are over built and the machined parts like flanges and shafts are impeccably machined using incredibly hard steel. The transmissions have oil pumps that pressurize the main and lay shafts to keep everything thoroughly lubricated so the bearings that the gears turn on are flooded in a pillow of oil.

This transmission out of this 250 shifted well but had the typical severely worn synchronisers so I was prepared to perform the “normal” repair of cleaning, inspecting and replacing the end bearings and synchros. This trans had been run without oil for a long time and the bearings in the photo were so wiped out that there was about .020″ clearance between the gear and bearing where there should only be about .005″. How did this thing work at all?

250 GT transmission overhaul

Transmission overhaul bearings

Bearings Ferrari transmission

Here is a totally stripped down 250 engine block known as basimento, or base to which the rest of the engine is attached. Looks kind of skeletal.

Ferrari 250 GTE

In the mind of every vintage car enthusiast, the Mille Miglia may supersede heaven as the location of divine happiness. This lovely 250 GT Pininfarina Coupe was named 250 MM, short for the race it was designed for, the Mille Miglia. Even this carefully crafted and beautifully prepared car is not immune to the the throes of classic car ownership. The devil is in the details.

Still looking for someone to explain to us why Ferrari went from the compact light weight and wonderful shifting transmissions in the early 166/195/212/225 cars to enormous and heavy cast iron transmissions on the later 250/330/365′s. Here are photos of the 330 2+2 5-speed and a 166 5 speed. There is about 100 lbs difference in weight and a considerable size difference. Did Ferrari use some truck or tractor transmission for these later cars?

The blue 330 GT 2+2 that came in earlier this year ended up needing an engine overhaul but I was fortunate to be able to drive the car prior to breaking it down. The transmission shifted perfectly but on acceleration/deceleration the shift lever moved back and forth significantly. As some may remember, this same thing happened to a 330 GTC transmission a few years ago and it turned out to be a loose ring nut on the main shaft.

I was certain that we had the same issue on this 330 2+2 and when I took off the top cover, it was instantly obvious that the ring nuts at the back of the main shaft holding the gear cluster on were totally backed off. They are doubled up to jamb together to prevent loosening plus there is a locking tab for extra protection on backing off… but still, someone managed to mess this up. Thankfully no damage was done to the internals.

Huge Ferrari transmission

Early Ferrari 5 speed aluminum transmission

loose ring nuts on a Ferrari transmission

Here are some more photos of the GTE transmission that I am overhauling. Everything else looks fine inside, we are replacing all of the bearings and synchroinzer bands. The main shaft and lay shaft gears are all in excellent condition.

Transmission

Gears for mainshaft and layshaft

but the gears and spacers are all good.

Last month we removed the transmission on a 250 GTE to have the overdrive that was inoperative inspected and rebuilt. When our friend John returned it to us, he mentioned that the filter on the overdrive was packed with metallic fragments that must have come from the transmission since nothing metallic matching this debris came from the overdrive. He told me that without removing, inspecting and super cleaning the transmission, there is no way the overdrive would last more than a few thousand miles.

I could not imagine what could have been a problem since it shifted well and was quiet when I drove the car prior to the tear down.

Yesterday I began to take the transmission apart and found that the Boccola ingranaggio, or 1st, 2nd and

250 Transmission gear

Bushing for 2nd gear

3rd, gear bushing style bearings are all torn up and the lead/tin coating has been wiped off the surface, probably from a low oil condition. I bet there was a pound of metallic sludge in that overdrive brass screen filter.

The new castings arrived and they look perfect. I wish we could get new parts like this for every component on Ferrari engines.

We also inquired about getting a new engine block for this project since the original may be compromised from all of the corrosion, but after hearing the price, I think we can fix the old block!

Water pump casting new and old