92 MIM Jazz Truss Rod Issues

bstringrandy · #1 12-29-2011, 07:34 PM

Sorry up front for the long post.

I have a 92 MIM Jazz that I picked up for $250. I had some parts laying around so I put a BAII bridge, DM model J PUs, and an Audere JZ3 on it. It was a great player for about 3 years.

I noticed the truss rod was bottomed out after I got it home, but the relief was okay. Anyway, I recently took it out and the relief was too much for me. Buzzing above the 12th fret that I could get out by raising the action but it wasn't close to what I'm used to. I removed the TR nut and put a single washer on it. The TR nut bottomed out and it didn't help the relief any. I "assisted" by pressing on the headstock and removed the string tension to no avail. With no tension, the neck had a lot of relief with the TR nut bottomed out!!

I then changed the strings out to the lightest tension I could find, D'Addario XL Super Lights. That didn't help much so I put another washer in and tried again. This time, the TR nut started to tightened and then "let go". I removed it and noticed that the threads didn't look too good, I chased them out with a 10/32 tap and tried again but it wouldn't hold. I removed the washers and the nut tightened up, but the neck was still bowed.

I decided to drop $5 on a new TR nut from Bass Parts Resource. It came in and did the same exact thing!!

At this point, I wonder if the TR rod threads are shot. If so, is the next step a replacement neck off of evil bay? There's about 30 of them listed and seem to go loaded with tuners for about $150. Wouldn't the repair bill go for that much or more? What to do?? It's a good bass that i don't want to consign to the parts bin!

bstringrandy · #2 12-30-2011, 02:30 PM

Does anyone have a guess what this might cost to fix by a reputable luthier?

If it involves pulling the fingerboard and replacing the truss rod, I don't see that being cheaper than getting another standard jazz neck.

narud · #3 12-30-2011, 03:07 PM

clamp the neck into backbow

take the tension off the rod before clamping it then max it. ill usually let it sit like that for 6-8 hours. ive never done it on a neck that was severely forward bowed to the point that light gauge strings wouldnt help, but its always worked for me with necks that the rod wouldnt straighten completely with a 105-45 set.

96tbird · #4 12-30-2011, 04:12 PM

That's dandy, but his threads are screwed up right down at the bearing point. Back clamping may not work if not enough good threads are exposed by it but it's worth a try as a starting point. Stewmac sell a kit to fix this but a new neck would cost less. If you watch the video, you can see how it works. I don't think you will find a bit like that though. Ridiculous price for that rescue kit.
STEWMAC.COM : Video of Truss Rod Rescue Kit

bstringrandy · #5 12-30-2011, 06:31 PM

Thanks!! At this point I have nothing to lose so I'll try the clamping approach and string it back with DA Super Lights.

I saw the Stewmac TR repair kit. For 200+ bucks, it might make sense for a repair shop, but as was mentioned before, for a single repair there are lots of necks available for less.

My main concern with clamping is that there won't be any adjustment left in the neck. As soon as I get a bigger C-clamp I'll give it a shot!

walterw · #6 12-31-2011, 12:49 AM

i've heard that an early run of mexi basses had bad rods, as in rods that weren't inlaid into the neck right, to where they won't pull the neck straight no matter what you do.

at this point, you don't really have a "good bass" so much as an old mexi bass body (poplar? basswood? likely not ash or alder) with nice parts on it.

i suppose you could look at a fender neck from someplace like "strat-o-sphere" on ebay, where they part out various models of new fenders.

bstringrandy · #7 12-31-2011, 10:21 AM

Yeah, I'm going to try the clamping approach. In the meantime, I'm watching about 10 auctions, some of them from Stratosphere!

bstringrandy · #8 12-31-2011, 10:59 AM

Okay, here goes nothing!!!

john grey · #9 12-31-2011, 11:13 AM

I have seen this same issue w/ MIM J-azz basses - interestingly I haven't seen it w/ a MIM P-bass. It's really possible that you would be putting effort and coin into a money pit.
I think from a realistic point of view you could do better hunting down a replacement neck - NOT on eBay; but from a reputable mfg. the cost would be comparable (or at least close) and you may find a neck that you enjoy a great deal more than what's there. My suggestion is that you keep your options open.

bstringrandy · #10 12-31-2011, 11:54 AM

Okay. I dif some rooting around on the web for replacement necks.

The Allparts are $300+ which are way out of the price range for this project.

Warmouths and Stewmac models can be had for $140-180.

I can get a Mighty Mite off of Amazon for $97. Are these decent necks for the money and how would it stack up against a 2008 or so loaded Fender Standard Jazz neck off of EBay?

96tbird · #11 12-31-2011, 01:59 PM

Well now you have it clamped is time to see if that nut will go on and hold. The neck has a lot of back bow now, the truss rod will be extended now. The only reason to leave it like that is if you are trying to correct a warp. Put that nut on and see where it's at. If it holds, string it up and begin backing it off to see if you can attain proper relief.

The Stewmac and Warmoths are unfinished, so there's that. If it were me I'd be looking for a real Fender just to keep things legit. I wouldn't be in a hurry. You Don't need a loaded neck; you have a parts neck.

bstringrandy · #12 12-31-2011, 02:39 PM

The nut threaded back on okay and I tightened it until it firmly bottomed out. I'll give it a couple more hours and see how it does.

I agree. If this doesn't work, I'd prefer to go back with a Fender neck if possible.

96tbird · #13 12-31-2011, 03:06 PM

I hope this works out for you!

tjh · #14 12-31-2011, 03:19 PM

Just a couple thoughts looking at your pics and reading your text ... I pretty much have had the same experiences with all the comments above, regarding earlier MIM Standard Jazz necks ... a couple quick thoughts, on these basses, I always completely loosen the strings, and place the bass between my feet, hold the heastock secure, and with my knee press into the neck slightly to correct the forward bow, and then attempt to move the truss rod nut .. another words, I dont rely on the nut to correct the alignment, but to secure it once I have put it where I want ... this wont help once there is an issue, but may help to avoid one in the first place with stripping threads on either nut or the rod, especially where the rod/nut used was questionable in the first place, as these seem to be ...

... in the picture you have posted, I prefer to have my neck fixed in the jig with a smaller conttact patch on the blocking, so it actually fits between the fretwires on the first and somewhere around the 18-20th fret, I have small blocks I have cut and rounded to match the FB radius somewhat ... I guess I just dont like using fret wires as a pressure point, and I wouldn't place it directly on the nut either ... also, I like to slightly move the pressure point on the back of the neck EVERY FEW DAYS ... another words, I loosen the truss nut and leave it in the jig for maybe a week, or even longer if its a real old neck (or if I forget it like I did one) .. my pressure is not great to start, and I prefer to put tweeks in small increments over a longer period rather than a quick fix ... tbird above mentioned no reason to keep it here unless correcting a bow, but I have found that the slow-go, easy at a time, sort of approach has been more successful for me in obtaining lasting results ... I am trying to slowly reverse the 'memory' the wood has had over the last 15-20 years of forward tension ... it would probably be different as he says, with a decent truss rod system and on a newer bass ..

... I am not a luthier, or even close, so certainly do what you feel is best, but as I described above has worked well for me ... on these aged, dried out necks, I have found if you move them too much, too quickly, it can create other issues ...while this one is 'cooking' I would actually look for another MIM Standard neck, from somewhere like on here, where the person more than likely will know, and be able to tell you the status of that neck and its truss rod .. I have seen them go pretty inexpensive ... all JMHO ... good luck with the project

jkjgiants26 · #15 12-31-2011, 03:22 PM

Loaded 1992 Fender Standard Jazz Neck on Ebay
1992 Fender Standard JAZZ BASS NECK & TUNERS | eBay

Looks like they knew you needed a replacement

bstringrandy · #16 12-31-2011, 04:02 PM

I know!

I'm watching that one but it's at a fixed "buy it now" price that's out of range for this bass... :/

Thanks tjh! I learned awhile back here on TB to assist the TR nut as you mentioned when pulling against the strings and I also loosen the string tension if things seem tight. This is the first one I've had bottom out with relief still left in the neck. I've got the blocks right behind the nut on the headstock end and resting across the last 2 frets on the heel end.

By the way, happy New Year!!

tjh · #17 12-31-2011, 04:04 PM

That looks like a good one alright, jkj ... but at a price most of the entire '92 MIM Standard Jazz basses sell for

...

Randy, I can be anal about these things, but I think I would prefer that both of my pressure points be on the fretboard, like first fret, in front of the nut slot, and not on the headstock .. JMHO

Happy New Year to you as well !! ... and to all ...

96tbird · #18 12-31-2011, 05:00 PM

I dunno, an MIA neck would be justified IMHO. What's a body? It's a pretty neck holder; the magic lives in the neck. An MIA neck for a few bills would likely elevate the bass. I would also write notes in the pocket for future provenance, that's me.

Anyway, I was surprised to see the neck already clamped to such a bow in so little time. I would be inclined to back it down a little if you're gonna let it sit. If it doesn't work out when you try string it up,; you hit bad threads again, I would personally try anything to hog some wood outta the hole before I scrapped it.

At that point there's little to lose. I might try drilling some out with a small bit and cleaning it out with a small chisel. Or Dremel with a long hogging bit. Or talk to a highly skilled woodworker that uses old school methods. YMMV.

Happy New Year!

bstringrandy · #19 12-31-2011, 05:13 PM

Okay, I'll back her off a little.

The pic didn't show it well, but the block on the headstock end is actually on the fretboard between the nut and first fret.

bstringrandy · #20 01-01-2012, 09:07 AM

Once again, Happy New Year!

I remounted the neck and restrung it with DA XLs. Initial results look great so far!

The neck was slightly backbowed unstrung and then pulled into a very slight relief under tension. No buzzing anywhere on the neck and the action is nice and low. It actually has less relief now than any of my other basses. I think I'll leave it that way to see if it pulls any more relief into the neck over time. So far, an $8 investment in a larger c-clamp is paying off!

Here she is back together resting in her case...