Dear Ferraristi, I may have to remove my alternator from my 91 Testarossa. I have searched the archives and they suggest I remove the top half of the intake. Do you have to replace the large gasket or can it be used again. Also, what is the torque spec for retighening the intake.? I came back from a trip and as I pulled to a traffic light, the car was lumpy at idle. When I pulled into my garage, it sounded off like it was missing. I checked the plugs, no fouling, checked the conectivity between the cap and all wires, nothing dead. I just finished putting all new plugs in ( tune up time anyway) and will measure voltage off the battery when idle and when reving. I was thinking Alt. as when I turned off the headlights, the car sort of went smooth. I remember a long time ago in my 308 a bad alternator left the engine running off the battery and the ignition started to go off. Will A TR exhibit the same symptoms in case of a bad Alt? Otherwise, the car has been running perfectly before this problem. Any opinions ? Shamile Freeze....Miami Vice !
Theres no need to touch the intake, just remove the two forward pieces of engine bay panelwork... the grille and the body colour section... there are just a few 10mm spanner size bolts underneath. Should get it off in an hour, more or less.
This was my very first problem with my TR and the gang at Flist said that it could be done but you need special wrenches! At least for the 86, there are two panels right behind the rear window that have to come off ( 6 mm dia. bolts hold the louvers and 6 mm studs hold the panel). After switching off the battery, remove the large output cable and small connector. On my car there's a large bolt (6" long) that the alt. pivots on and and when you try to remove it, it hits one of the radiator coolant lines. There is also an upper adjustment for belt tension that has to be removed. My solution was to remove the retaining bolt on the leading driver side motor mount, loosen the rear driver side motor mount bolt and then get a small scissors jack and lift up the front corner about 1.5 inches. Go slow and keep an eye peeled for other hoses getting stressed. There is a cooling cowling that may have to come off the alt. before you can wiggle it free. After getting my diodes replaced, I replaced the alt. v-belt pulley and forever cured the belt slippage/smokage problem....but that's another story . YMMV Jeff Pintler 89 348tb, 86 TR
On the large bolt that the alternator pivots on there is a thin shim washer. be aware that it will fall out when you pull the bolt and lift the alternator out. Brian
Dear Ferraristi, Many thanks on the advice. I'm "gut" guessing at the "lumpy" idle right now, but my past experience with my 308 and its ignition going flakey as it was only running off the battery was guiding my thoughts. I'll see if anything's going on tomorrow with some testing. Shamile Freeze.....Miami Vice !
Dear Ferraristi, False Alarm ! I tested the alt and it registered a 13.97 volts at the battery at idle with all lights, AC and the cooling fans running. I then checked all wires for conectivity...all fine. I put a new set of plugs in and voila! Funny though, I only had about 7500 miles on the last set and only replaced 1 yr ago. I drive the car as a daily driver so don't freak out on the mileage. The car even sounded better and reved better. What can make a plug go bad? I don't have fuel issues as the car was balanced last yr and starts fine and warms up fine with no fuel smell (no cats ) Shamile Freeze...Miami Vice !
Ive fitted brand new spark plugs from the box that have been faulty from the factory and have caused headaches because of it. Good you got it sorted anyways!
Vince: Sorry this has taken so long to get back. I didn't eliminate the v-belt, I got a slightly larger diameter pulley for the alternator. My stock ferrari part was aluminium with a very slick coating and the stock belt just fits in the v such that the back of the belt lines up with the outside diameter of the pulley. The replacement pulley was a half inch in diameter larger and the Conti tech belts (made by contenential and a bit narrower than gates) fit down into the v about 1/4 inch from outside diameter. So the belt is less likely to get flipped off and the larger diameter increased the torq imparted to the shaft. I haven't had a problem after three years of service. I think I can send a jpeg showing the two pulleys if you send a private message with an email address. FWIW Jeff 89 348tb, 86tr
Hi Jeff, I have the same problem with my TR burning up Alternator belts. At first they squealed and I would tighten them so the were adjusted correctly. A couple hundred miles and the belt would burn up. The pulley is polished like chrome. Do you have a part number for that pulley and is the belt the same as original in length? Any help is greatly appreciated. Pete
The search function in your friend. Hope this works! The PDF file are comments from a previous postings and the picture shows the steel pulley from my local alternator shop. These are common alternators in US cars and trucks. Once you find one that is close, a machine shop can modify it to fit perfectly. Five years without a problem. The hardest part of the process was getting the cat to hold still! Good luck! Jeff Pintler 89 348tb, 86tr, 99 360 3-pedal Image Unavailable, Please Login Image Unavailable, Please Login
This was one of the first things that my 86 needed. The big problem is the lower alternator pivot bolt hits the rigid coolant tube. So rather than tear apart the cooling system, you can remove the driver side motor mount nuts (big ones, not the little ones) and jack up the driver side (sissors jack and block of wood on the pan bolts) so the pivot bolt clears the tube. There is enough compliance on the pass side mounts that you don't have to loosen them. Of course you will need to remove the grill and panel behind the window and an air cooling shroud on the alternator. You don't have to remove the inlet manifold or the engine cover. Use a moving blanket to lay over the fender. One time I was really pissed and the alternator was removed in about an hour. If your car still has the v-belt, I found the contitec brand is slightly narrower than Gates and rides down in the "V" better. And you change the v pulley to a slightly larger larger diameter with a deeper V so there is less "smokage". Good luck! OK so the paste function works. Even though the pulley is larger in diameter, the belt contacts the "V" down inside and withthe larger pulley, more torq is transffered to the stator. I like the steel finish instead of the annodized factory pulley. The new belt was slightly larger in length, maybe Contech AVX 10x850 but of course that is dependant on the pulley you find. I also measured the output of the new setup and found no change in charging. I think the alt. turns 7% slower but can't find the notes from the repair 8 years ago. Image Unavailable, Please Login
One caveat about changing pulleys -- when I had problems with my 328 alternator and the factory pulley was damaged beyond use, I tried to get one from the Bosch alternator shop I had taken the alternator to for a rebuild. The owner who had been rebuilding these things for over 40 years told me that the pulley used by Ferrari on the 308s and 328s was proprietary, and was not a stock Bosch pulley. Ferrari had the pulleys made specifically to provide the proper offset with the damper. Fortunately, Ricambi America stocks a replacement pulley made by Hill Engineering. I was able to buy the replacement which is a very well made, anodized piece. And it was not terribly expensive, like some Ferrari-specific parts. It fit perfectly and lined up beautifully with the damper when the alternator was installed. If you are changing the pulley, be very careful that the pulley lines up with the damper and that the belt is running absolutely straight. Even a slight misalignment can lead to the belt wearing and premature failure. Just a heads-up on that.
Great comments about about checking alignment. The rebuilder shop's comment about propietary parts is cr#p, there is nothing special about alternator pulleys other that proper fit. After you hold the original pulley for the TR in your hand, you wonder why they used a very slipery annodizing and a narrow "V" that the belt is 1 mm above the outside diameter (yep, even with the factory belt). The pulley I found was machined for shaft diameter and back spacing length. I burned up a couple of belts before fixing the problem and the original part was poorly designed. Easy $4.00 fix. Jeff Pintler 89 348tb, 86tr, 99 360 3-pedal
I can think of a few possible reasons: 1. the same reason that the dash and door card panels are that ridiculous "plastic straw" material = weight. 2. They were going for less power loss (ala the tiny alt belt on early 308), but found it wasn't adequate to drive a big alternator. It seems crazy to me, too, that anyone would intentionally design a V-belt system where the depth of the sheave is less than the belt height. I'd go more with that they intended to use a smaller cross-section size V-belt, but changed at the last minute when they had trouble -- they tested it, and (wrongly ) felt it was OK. (The figures in the early TR OMs and 1987 TR SPC show the V-belt does sit down fully in the groove, and seems a smallish cross-section, "notched" V-belt). 3. they got nervous about the lower alternator RPM at idle issue that you mentioned, so they needed, and went with a custom pitch diameter size (i.e., chances of operating with every electrical device "on" at idle for an extended period is near zero, but they have to plan for that). 4. Vendor or drawing error -- the parts come in, they realize something isn't quite right, but they tested it, and (wrongly ) felt it was OK to use up the parts as-is. Just some random thoughts (but I'll go with #2)...please post a sketch of the alt pulley modification/dimensions, if you have one.
Great tip! Jeff, I don't know if I missed it, but what was the part number for the larger pulley and what car was it off of? I can't find it. Bo
Bo: Sorry for taking so long getting back to you. The pulley I found was just hanging on a peg at my local alternator repair shop. You can sort through their collection to find one with the correct diameter and substantial center that can be machined to fit. I was just at the place yesterday and grabbed another one that would work for $2.00! Remember these Delco-remy (10sy I think) alternators are on lots of cars and trucks. The speific pully installed on my car is 2.725 inches across the belt vs. 2.335 inches for the stock aluminium pulley. also know that a 16% increase in the pulley diameter does NOT reduce the alternator output by 16%. The alternator is turning at 1800 rpm at an engine idle of 900 rpm vs 2100 rpm using the slick, belt smoking stock aluminium pulley....I measured 46 amps at an idle. The belt is AVXx10 by 900 or AVXx10 by 838 mm (one is for the air pump). Goodluck! Jeff Pintler 89 348tb, 86tr, 99 360 3-pedal Image Unavailable, Please Login
Thanks! I will look into this, sounds like a simple fix... I can't believe how tight the stock belt has to be to prevent slipping/squealing... I was even thinking about sand blasting the pulley to give the belt some "bite." Bo
On reinstalling, I’m having trouble aligning the pivot bolt through the alternator body and its associated threaded bracket. I’ve aligned so that the bolt slides through the non threaded bracket, the alternator body, and then comes into physical contact with the threaded section towards the back of the car (circled red in pic). I can’t seem to get the threads to engage. One possibility is that either the bolt or bracket threads is messed up, and my plan is to pull the alternator out and see if the bolt will engage without the alternator in place. That’s a royal pain, and before I do that I’d like to make sure I’m not overlooking some simple technique for aligning the bolt holes. With the space constraints I’m only able to pry up/down as seen, I can’t seem to locate any other point to exert sufficient force to move the alternator, its seated pretty tight. Any pointers or thoughts? Image Unavailable, Please Login Image Unavailable, Please Login
I know this is going to sound a little crazy, but you could counterdrill the thru hole in the alternator on the side going to the threaded bracket slightly some to give the threaded bolt end more "wiggle-room". 2nd crazy thing is: is the thru hole in the alternator is a simple thru hole and not a stepped hole? In your photo with the pry bar, the amount of exposed bare shank on the bolt looks much longer than the length of the female threads in the bracket (if you've got the bolt pushed in as far as it will go before starting to thread in).
If you put on a pulley that too big, you won’t be able to get the bolt through… I upsized the pulley slightly “eyeballing it” and it barely went back together as the belt made it tight. But no more belts flying off… working great for 13 years. Rarely when you first turn the car on the alternator light goes on, probably because the rotational speed is too low. A slight blip of the throttle, and light goes out, works fine…
Well, I reluctantly pulled it out and I could see that the bolt thread was slightly worn off at the starting end, so I used a die to clean it up. I then carefully aligned the alternator in its brackets using hex keys to probe for alignment at both ends. Then push/pull on the alt while screwing the bolt so that it wasn’t binding. That seems to have done the trick and the bolt threads now. Not very satisfied with the whole setup as now it’s extremely tight and I can’t rotate the alt around the pivot bolt by hand like I previously could. The adjuster bolt does make it tighter. Going under the car the belt looks proper around the crank pulley, at the alt pulley it looks like it’s one rib outside of the pulley. With the tight setup I’ll have to fight to get the belt over the top pulley or will it self align if I try to start the car? Image Unavailable, Please Login Image Unavailable, Please Login
I wouldn't -- the multi-rib belt need to be in the proper place on each pulley before rotating the engine. Welcome to the typical TR project -- "Some fiddling may be required" .
