Bilstein 5100 and 4600 combo

Hey everyone, just wanted some advice regarding my plans for upgrading my suspension. After initial thoughts of wanting to lift my truck upwards of 2 inches, I've decided I want to go with an OEM+ look and simply level the front. Bilstein 4600s have been installed on all four corners a couple years ago. I want to install some 5100s in the front and use the OEM springs to adjust the front up to near level. Would I be okay with keeping the 4600s in the rear? They still seem pretty solid, and I feel like it'd be a waste to swap them out if they have a lot of life left in them. I don't have a camper shell, and I don't typically haul things around often. I understand that the shocks are almost identical, but the 5100s do better at handling heavier loads/tires (based on my quick research). I'm also running stock size tires right now (265/70 R16), but I do plan on upgrading to some Falken Rubitrek pizza cutters (LT235/85 R16) soon. Thanks in advance for any input/advice.

 

You’ll be fine. If you are happy with the ride of the 4600’s in the rear, you can keep them. They are very similar to 5100’s, but I prefer 5100’s between the two.

 

This is going to be an unpopular opinion around here but if your 4600's are new and your goal is just to level and you're happy with the ride why not just run a small strut top spacer up front? As long as you extend the bump stops so that they still do their job I don't see the problem.

 

I think this is what JDM Driveway runs and it looks pretty good. Would save a lot of money too if the 4600s are still fine.

 

^ what they said.


If you're willing to spend a little more you can go with an OME lift spring.

Which can transfer to 5100's in the future and provide a reportedly better ride.

 

Because strut spacers are overall a really shitty thing to do, pushing your overall suspension downward w/o adjusting other things. Happy to link you with a video that explains it in greater detail if it's difficult to visualize or you're new to suspension.

Several observations:

• You can mix and match any front/rear shock you want
• Be aware: 5100 is effectively the 4600 with an aluminum body; valving supposedly similar enough it's virtually unnoticeable if 5100 is at bottom notch, but 5100 includes a movable perch to let you raise/lower.
• Knowing that, why bother spending $600+ on new 5100s up front when you could keep your 4600s, buy some OME 2883 springs for $250 (or 2884 if plan to lift rear and want another ½"), with these updated KYB isolator adaptors for OME springs, and have a better overall ride for half the cost? Just swap springs and isolators onto your 4600s and you're done.
• EDIT: adding the spring fitment info from THE 1st GEN COMMUNITY MEGATHREAD to the end of this post, I see for 2WD/AC we don't recommend the 2884, there's a squat risk.

Look, if you want the 5100s for adjustability, cool. Just know, with the stock springs, every circlip you raise things, your ride will get progressively harsher. If you opt for a lifted spring like the OME, and pop it into the 4600, you'll keep the same preload, and probably enjoy a more OEM-like ride.

Fitment info on OME springs for our 1st gen trucks:

• Guidance to pick the right lifted spring w/Bilstein 5100/4600: With OME (Old Man Emu, not 'OEM') springs, it can daunting which spring to pick, between the 2883, 2884, 2885, 2886, 2887. We have tons of user experiences and know what you can expect better than any vendor:
  • You need these isolators for OME springs
  • For AC/RC with 2WD, both V6 and V8, you'll get near-level with OME 2883. Don't do 2884 unless you plan a rear lift.
  • For AC/RC with 4WD, go 2883 for a sport rake, 2884 to get level, don't go with 2885 unless you plan a rear lift
  • For nearly all DC applications, you'll get a bit of rake with the 2884, level with 2885, and if you plan a rear 1-2" lift, 2887 is probably your choice.
  • With any suggestion given here, your lift may take a bit to settle at final height.
  • If you're AC/RC be forewarned: Nearly all who doubted the above were left squatted out back, thinking 2884 or 2885 was right for their AC/RC 2WD truck. It'd just not the case, and a lot of vendors don't know/bother to inform their customers, so heed the above.

 

OK, since we have two people posting "use spacers" advice, I'll just link the video.

This covers the ins-and-outs of why spacer lifts are bad, in very clear, easy to understand terms. Front spacers start at 8m22s which I'll set the video to auto-jump to. If you want to see why rear blocks suck, jump back to 5m30s.

https://www.youtube.com/watch?v=ihErEq6SRrk#t=8m22s​

 

Not new to suspension at all, been messing with it since the late 80's. Tinker's first issue with the spacer is a non issue if my suggestion on the bump stops is followed. As for control arm contact that can happen with a set up like 5100's and on Tacomas it still does and might also be prevented with taller or spaced bump stops. I've owned trucks lifted about every way you could lift them and while IMO a spacer is the least preferred, it is not such a terrible thing if kept to a reasonable level which on a Tundra seems under 2 inches. When I do mine I'll do either 5100's or Eibachs as I feel that will give me the best combo of ride quality and affordability. Since he was looking to level the leaf blocks should be a non-issue.

 

Thanks everyone for the advice, especially @shifty` for laying out all my options. Now I’m torn between using an adapter and new springs with the 4600s for the front or going the 5100 route with OEM springs. I’m leaning towards the former… Once the work is complete, I’ll circle back to provide some feedback. As always, this community is awesome. Thank you!!!

 

I'd be lying to you if I said, "I've never recommended such a thing before!" on here. There's a time and a place, especially for fixing "Tundra lean" and for people who really don't know what they're doing and just want to lift the front end a bit to ditch the hardcore rake - but recommending the latter is a mistake I failed to realize until later. But in the case of the 1st gens, specifically, I wouldn't do anything larger than ½" shim, IIRC ratio is 2:1 on lift:spacer. It appears that somewhere in the 1½"-2" range is where people start running into issues with UCA clearance against the spring at full extension. But in general, the extra torsion on the UBJ, which normally doesn't see a ton of stress, is bad news.

The unfortunate problem enters the picture when people w/strut spacers decide they want more lift, and install lifted struts in tandem with the spacers. This is where ignorance comes into play, and not "ignorant" meaning "stupid", I mean ignorance in the sense of "don't know better". We've had some fun situations on this forum, this is always my favorite to link folks to. This one kid straight-up fucked his shit up, bent knuckles, it was a total mess. My guess is he went to a shop that typically does Ferd and GM lifts and isn't aware of the general challenges and problems with the front suspension/steering on the 1st gen trucks. Not that I'm the authority on that, but ... I speak for everyone in this 1st gen subforum when I say, "We seent some shit"

 

I have 5100s in the rear and 4600s up front, with OME (not OEM) 2883 coils. I'm actually really happy with the ride. I probably wouldn't be if I had kept the OEM coils and used 5100s on a higher perch.

 

100000% agree on strut spacers.

As to 4600 vs 5100, I know the consensus is that valving is essentially identical but I did not find that to be the case. I’ve had 4600s and 5100’s on my vehicle back to back and found the 5100’s to have an improved ride, even set at the lowest setting. But that’s simply my anecdotal evidence.

In one of Bilsteins podcasts, the topic was brought up and I believe one of the Bilstein guys said something to the effect that they were virtually the same, but then quickly backpedaled to say they ride about the same to most people. So maybe my use case or butt dyno were simple different enough to notice a difference, but the vehicle was otherwise stock.

 

Good choice in getting new springs. I installed the 5100s on the 3rd perch with my original springs. The ride was HARSH. I bought OME 2884s and installed on the first perch and the ride is noticeably better. The 4600s are fine struts. I had them on my '95 Tacoma and I loved them.

 

I’ll chime in too. I personally don’t like and wouldn’t use a spacer lift. That said I would use spacers to lift and level the front end. To clarify, I’m specifically referring to plastic spacer no more than .5”, not those bolt on strut spacers. They can usually be found in .5 & .25” thickness. I wouldn’t go over the 2nd perch on 5100’s. Nothing wrong at all with ome, another alternative are Toyota springs from bigger models from junkyards. I lifted my runner with 2nd gen taco trd springs, could maybe get lift from sequoia springs, as it’s heavier than a tundra or go forward a gen, again heavier vehicle. Best