Hitachi LR160 60A alternator

[asavage]

More information and pictures are in the Hitachi LR150 50A alternator thread, which is a substantially similar though smaller unit used on the 720 pickups, and the Diesel Tachometer thread, which shows modifications to bring out a stator tap, that can make adding a tachometer easier.

This is not (yet) a complete, "How to rebuild your alternator" post. Just some semi-organized pics I've taken over the course of the last three LR160s I've had apart.

Background: this series of Hitachi alternators (both the 150 and 160) have main diodes that are fragile. The solder joints die, but more often the diode frags and physically comes apart. See the pics in this post, and some close-ups about ten pics down in this post. On the Maxima, the symptom of a failed alternator -- for whatever reason -- is about five of the dash lights lighting up all the time, or in my case blinking on and off in unison. That's due to the way the bulb check system is designed. This will not happen on the LR150 in the 720 pickup, which does not utilize a bulb check relay.

If you have to open up an LR160, you will probably want three things in hand at a minimum (prices are as of Aug08):

• Brushes, bare -- Standard JX118 (NAPA, $5)
  or
  Neihoff WA547 (has un-needed wire insulation)
• Rotor oil seal, double-lip -- Rexco 41-81700-1, $5
• Diode assy. -- Rexco/Transpo IHR607, $40

Optionally, you may want to replace the bearings:

• Front (drive end) bearing 6303-2RS (NAPA - specify "SKF" brand, $33)
• Rear (idle end) bearing 6303-2RS (NAPA - specify "SKF" brand, $8 )

In practise, the OEM or quality replacement bearings are fairly robust, and the rear brg does require a split bearing puller to remove. If it's been "rebuilt", the replacement brgs are often/usually not a quality replacement.

So far, every non-working Hitachi LR alternator I've opened up has had a bad diode assy. Most have needed brushes. Some have needed bearings. And the oil seal is a "replace always" item.

Hitachi-rebuilt alternators (ie, an alternator you'd get from Nissan, like the one I have below) have the same, weak diodes as the originals

(click on any image for larger)

Remanufactured for Nissan
(Nissan Part No.) 23100-W2502-R
(Hitachi No.) LR160-97C-R



The voltage regulator is reputed to go bad on these. So far, I've found only one bad one. My rebuilder replaces them automatically, but he has a warranty to honor. I generally roll the dice and reinstall the old one. They are not particulary cheap.



Once you unbolt everything, you have to desolder the three stator leads from the diode assy. A std. soldering gun of moderate wattage (eg 100w or more) will do fine. While I have a desoldering station, I find that using compressed air on the heated joint will blow out the solder OK, though a bit messily -- you will have to wipe/brush off the solder particles, and you definitely don't want to be breathing hot lead fumes so do this outside, if you use this method. Canned air works fine, no need for an air compressor.



Old (bad) diode assy. on left, new better-design assy. on right. The voltage regulator (yellow lead on left) has to be soldered to the black lead on the new assy.



VR soldered to new diode assy. Note that this diode's part No. may result in a cheaper Transpo branded unit. This one is the correct heavy-duty part, but another one I bought later has this same Rexco number but over a Transpo box -- it's going back to my distributor tomorrow.


Three pics of the same heavier-duty diode in the new diode assy.



VR soldered to new diode assy. (reverse side pic).



Solder the three stator leads to the new diode assy.



Rear housing, showing oil drain hole. If the rotor seal fails, oil may drain out the back of the case via this hole -- if you're lucky.



Drop the stator/VR/diode assy. in place, after installing the B+ insulator bushing. It all fits, really it does




OEM spring setup, about 1" of compressed spring length. It's much easier to buy the brushes loose and solder their pigtail to the old brush terminal. You may be able to special-order them already assembled, but I tried twice and kept getting the wrong part. Since then, I just buy the brush and solder them up myself. Getting the old lead desoldered is easy, but clearing the old hole of solder (so you can insert the new lead) can be troublesome. Use the canned air/compressed air trick again, works a charm.



The OEM-style rear bearing has integral silicone seals to the housing. They might help keep oil from a leaking rotor seal from getting to the winding side of the brg, but I doubt it. I buy a standard off-the-shelf bearing to replace it.

[diesel-man]

I have an Alternator for a 720 Diesel pickup to rebuild and was wondering about the transistor on the back end of the 2 prong plug (Maxi has a 3 prong plug). I think this is the only significant thing different between the Maxi and 720? Is that right? (50A vs 60A)

Anyhow it would appear that the Maxi diode assy should fit the 720?

I have only used the Nissan diode assy so far, although I saw someone on ebay selling some for like $21 or so apeice (according to memory). Never heard of Rexco, can you elaborate on the different brands HD or standard?
Thanks Wayne

[asavage]

I have an Alternator for a 720 Diesel pickup to rebuild and was wondering about the transistor on the back end of the 2 prong plug (Maxi has a 3 prong plug). I think this is the only significant thing different between the Maxi and 720? Is that right? (50A vs 60A)

As an assembly, someone has hung the whole LR160 onto an SD22, only ignoring the extra terminal, and it was a bolt-on.

I think the voltage regulator is different enough to not be interchangeable, though they look similar.

Anyhow it would appear that the Maxi diode assy should fit the 720?

I am pretty sure that none of the other major parts will interchange either (excepting the oil seal and maybe the brgs?), not the diode assy though it's constructed the same. If it would fit, using the 60a diode assy would buy some headroom for the 50a stator/rotor. I remember thinking, looking at them both, that the two diode assys are built on a horseshoe-shape frame whose radius is different from each other. But I could be wrong.

I'll see if I still have one of the bad LR150 (SD) diode assys. in a box somewhere, and if I do, I'll compare it with an LR160 version.

I don't really know anything about the different suppliers of parts for these. Rexco is what my local guy uses primarily, so that's what I get.

I showed him the different diode styles on the same Rexco part No.'d box today. He said both were actually Transpo parts and proved it by showing me the older Transpo labelling, which matches the older Rexco box flap I have. He's ordering me a LR160 diode assy from a third supplier next week to look at (I had to commit to buy it, either way).

[asavage]

Anyhow it would appear that the Maxi diode assy should fit the 720?

Looks like you are on to something, Wayne.



If the LR160's 1/4" wider base plate will fit the LR150's rear housing, I am not seeing any reason why the LR160 diode assy. can't be used in the LR150. I'd still use the LR150 VR though.

[goglio704]

Does anybody have a source that would list the Beck Arnley part number for the LR160 alternator's voltage regulator? I have found a source for a large quantity of NOS Beck Arnley voltage regulators at a cheap price and would like to verify the part number. I have emailed Beck Arnley because they don't list alternator parts on their website. The number I have is 177-0551. The seller indicates it as being applicable to the gas or diesel.

[asavage]

My FLAPS can't find a BA number for the LR160 either.

[goglio704]

Interestingly enough, I did find an excerpt from the Transpo catalog that indicates the LR160 regulator is applicable to many other alternators. It also indicates that there is a heavy duty version available. Al, I gather that Transpo is not your preferred brand, but I thought the reference material was interesting anyway.

[asavage]

I've used Transpo stuff, it's just that the last diode assy. I got from them has the OEM-style diodes, which I already know don't work long-term.

My local rebuilder says the ones that look beefier aren't really any better though

The VR from the LR150-133D (SD) is a TR1Z-64
The VR from the LR160-97C above is a TR1Z-64A

Transpo's universal replacement regulator is the IH212 (and the IH717 for longer warranty coverage ). Your linked page references the non-A version only, but I doubt it makes any serious difference.

Though I had been replacing the VRs as a matter of Good Shop Practice for the first few Hitachis I went in to, I've stopped replacing them for the last three, as they do not seem to be the first thing to die -- the diodes are.

[goglio704]

Al, since the diodes are a weak link, have you considered an external three phase bridge? It would probably be expensive initially, but it would sure be a long term solution. I bet these guys could come up with something bulletproof. I like the type W.

http://www.cehco.com/rects.htm

[asavage]

Yeah, I've considered -- and discarded -- the idea of external diodes after I had my first Hitachi apart and saw how they break.

I am too cheap to buy them, I would rob them from some other alternator, then find a suitable chunk of heat sink material and attach them -- somehow.

However . . . they must be guarded. Put in a cage. Then then need positive airflow. Bringing out the six leads from the stator is not trivial, as you transition from solid to stranded, do vibe isolation of the harness and strain relief, and loopback to the VR (or remote the VR too, then just loopback for the brushes and OEM connector).

By the time I did that, I'd be much better off buying a new electric vacuum pump and a JY Delco from a Cadillac or similar.

And, finally, yes: the diodes die -- after a life of eight to twenty years. Delco alternators die in that range too, but from multiple failure causes, not just the diodes. In the big picture, the reliability of the LR-series alternators is Good Enough to get the job done.

---------------------------------------------------------

Now seems a good time to qualify myself WRT alternators.

Back in the day when I was young and handsome and knew everything, I owned a Hillman. Actually, several (as of this writing, I have owned 79 cars & trucks; no idea how many motorcycles). This is the 1960 Hillman Husky that I drove the most, of all the Hillmans that passed my way:

This picture was taken in about summer 1981 at Useless Bay Golf & Country Club on South Whidbey Island at the maintenance shed. This was a $60 wagon my friend Nick Nilsen & I purchased in Seattle's Wallingford District in the pouring rain, basically bought it for the radiator for Nick's '61 Minx Convertible (purchased new in Israel). Somebody had fiddled around with it years ago and made it stop running -- basically took the distributor out and couldn't get it back in time. Patting myself on the back here, with a large umbrella and lots of supplies, I had it running in under an hour, and I drove it home from Seattle to Whidbey that day. The radiator did get scavenged, but I later bought the little Husky from Nick, found another radiator, and drove it for years. Hotrodding the little 1390cc too many times eventually melted a piston, and it knocked pretty badly for a couple more months, then I retired it. Gave it away, got it back a year later free, drove it a bit more, parked it and started it up every so often, transplanted a much better engine into it, then broke a ring on that engine (which was overbored) by over-revvng it drag racing a Celica in Everett. Then I loaded every Rootes part I owned into a large dump truck and took it all to Ralph Wigington's place in Lynnwood: "Hillman Restorations". Ralph, RIP, was a real gentleman and I miss him though he's been gone since about 1989, heart attack in Tennessee.

Most of the above was just me bloggin' and putting stuff down because I do forget sometimes. Which is why I actually made a "Cars I've Owned" list in 1985: I was already forgetting some of them.

This first pic . . . OK, I'm repeating myself. It was taken with a Polaroid Land Camera Model 900 that was my Mother's first anniversary gift to my father. This is the camera that documented my early years, and Dad long ago had moved on to newer photographic tech, and I inherited it. In 1981, it was at that time a major anachronism, with it's multiple batteries and slide-out bellows. It was useless for landscape photography, but excelled at sharp, high-contrast close work. I still have pics I took with it 25 years ago that are very nice. Color film was available for it, but only if I ordered directly from Polaroid, and in fact that's how I got my last half-dozen rolls of B&W film. I gave all my Polaroid stuff to a thrift store in Everett in 1999. This picture is not a good example of what it could do.






Working at the golf course, I was driving out one day and a group of high school golfers on the driving range. One particularly wild ball nailed my windscreen. Spare glass I had; spare glass rubber I did not, and never did find good rubber. I got several tickets for having a bad windshield.

Bumper became 4" pipe. I forget why I didn't try to re-affix the OEM bumper, but it had been attached via nuts tack welded onto sheet metal (I am not making this up) and the first time you try to pull on the bumper, it tears off. I had this pipe welded on, which was simple enough. However, it had to also accommodate the hand crank. Yes, hand crank. Though still optional, it was available still on the Husky in 1960, and I found the handle and the crank nut was sculpted to accept it, so I bored a hole in that pipe bumper, with a cross-slot for the handle engagement pin, and used to hand-crank start the Husky every time I took it on the ferry and at parties. When you ride a ferry, you have to shut off the engine, then start it after docking. I always made a production of getting out and hand-cranking the car when preparing to depart the ferry.



For scale, here is a quite presentable 1960 SdV (not mine, found on a side street above the Edmonds ferry terminal about 1982). On a memorable trip to LA in 1984 or so, I found I could just barely sleep in the back with the interiour out and me laying at a diagonal -- I was still pretty young. My younger brother & I drove straight through, of course.


On a camping trip, three friends & I took it to the beach north of Fort Casey, pitched a tent. Woke up in the middle of the night (drunk) to find the tent flooded: not above the tide line. Got Husky stuck in the sand, I could pick up one rear corner, tire off the ground (I had a better back, back then).

I would buy another Husky just for the memories.

A Polaroid Model 900:


So, with all that preamble out of the way . . .

The Hillmans of that era were positive ground. Much later, I learned that almost everything on it would work perfectly well either polarity, but early on when inevitably the generator conked out (Yes, it was Lucas; no, it did not suffer from unreliability, only old age, like the Hitachis), I would cycle spares through, but I don't really like generators, I like alternators, and especially the external-regulator Delcos from 1964-72.

While juggling Delco parts, for some reason I had opportunity to hold in my hand a couple of replacement diodes. Both positive and negative diodes. And you know what? They are physically identical, and press in to the Delco's heat sink. Light bulb came on!

I pressed out all six diodes from a Delco heat sink, pressed them back in in reversed locations. Voila: positive ground Delco alternator. The external voltage regulator is just a pair of relays that don't care about polarity. It works splendidly. I fab'd some brackets and mounted it in place of the lovely old Lucas gennie, and that 37a alternator remained there, trouble-free, for many more years.

I've always thought that that was especially clever, but I've never gotten much in the way of admiration at dinner parties when I tell this tale. I must be hanging out at the wrong dinner parites

[Carimbo]

On the Maxima, the symptom of a failed alternator -- for whatever reason -- is about five of the dash lights lighting up all the time, or in my case blinking on and off in unison. That's due to the way the bulb check system is designed.

Is this a definitive indication of failed alternator? My car had started flashing the door open light intermittently, most often when accelerating hard from a stop, esp. uphill. Dome (ceiling) light would light up at the same time, yet the interior lights on the door panels would not. I had thought it could be a wire shorting out somewhere in the door light switch circuit and put it on my list of things to track down.

Last night more lights lit up more steadily (Battery, door open, brake, and those on the strip along the top center of the dash-- fuel filter, seatbelt, tail/stop light) and was able to measure voltage at idle at the cig lighter w/ no accessories: right around 11.8 - 12.4V instead of the more normal >13.4V.

Alternator cover was also very hot to the touch, didn't think to sample it w/ my non-contact thermometer.

Is it time to swap in my spare alternator or are there other tests I should perform first? I have a DVOM, and will attempt the troublshooting table in the FSM p. EL-23.

I did look at the brushes; they were approx. 15mm long.

[asavage]

Is this a definitive indication of failed alternator? My car had started flashing the door open light intermittently, most often when accelerating hard from a stop, esp. uphill. Dome (ceiling) light would light up at the same time, yet the interior lights on the door panels would not.

While I don't know off the top of my head about that, it sure sounds like a door switch that is not quite opened when the door is shut.

Last night more lights lit up more steadily (Battery, door open, brake, and those on the strip along the top center of the dash-- fuel filter, seatbelt, tail/stop light) and was able to measure voltage at idle at the cig lighter w/ no accessories: right around 11.8 - 12.4V instead of the more normal >13.4V.

Alternator cover was also very hot to the touch, didn't think to sample it w/ my non-contact thermometer.

Is it time to swap in my spare alternator . . . ?

Yes, it's time.

Diodes break and go high resistance, output current & voltage drops, VR increases field voltage to try to get the output higher, and the delta V between the field voltage and system voltage gets the Bulb Check relay toggling, which lights the dash lamps.

Change it out. [And give me or sell me the spare, if you aren't going to turn it in for a core and aren't going to try to rebuild it yourself -- don't toss it -- the diesel rear housings are unique.]

[Carimbo]

Change it out. [And give me or sell me the spare, if you aren't going to turn it in for a core and aren't going to try to rebuild it yourself -- don't toss it -- the diesel rear housings are unique.]

Thanks for the good advice. Swapped in the spare alternator I pulled from the PaP last year; appears to be working fine.

Needing a working spare, I won't toss the failed one. It has a factory original looking sticker on it, not reman. Could be original? Planning to replace the diode assy and rear seal as per your helpful posting above. Wish me luck sourcing the parts, the rest looks straightforward.

[asavage]

I can get you the diode assy (about $40 with tax) and seal (about $5), if you can't find a better source. Or, I think I've posted Townsend Electric's phone number before, and you can call him direct. Or find a Rexco distributor in your area, since they're based closer to you than to me.

[83_maxima]

You've inspired me Al.

My alternator bearings squeal something fierce. I'm going to swap the rebuilt unit out of the parts car into mine and then rebuild mine!

Posiible Source for all parts needed to rebuild LR160:

WAI (WRS)

They have an office here in Denver, so I will be in contact with them to see if they can do small quantity orders of the parts I need to rebuild the alternator. They seem to stock just about everything needed.